Social media experts say they have found a shocking connection between online traffic in downtown Baltimore on Monday and activity recorded during last year's violent protests in Ferguson, Missouri. A leading data mining firm, which has asked to remain anonymous because of its government work, claims that between 20 and 50 social media accounts active in Baltimore on Monday were also used some 825 miles away in Ferguson during the peak of last summer's violence following the death of Michael Brown. The firm said the link suggests the presence of 'professional protesters' or anarchists who are in Baltimore and are looking to take advantage of Freddie Gray's death to incite more violence. Scroll down for video . A leading data mining firm claims that between 20 and 50 social media accounts active in Baltimore on Monday, above, were also used some 825 miles away in Ferguson during last summer's violence. Not all the accounts called for outright violence, but at the very least, the tweets were menacing and ominous, reports Fox News. One account - also linked to the recent union protests in New York City and other disturbances - tweeted photos of Gray's funeral and used language anticipating Monday's violent clashes. The data mining specialist described the discovery of so many of the same social media accounts in the two cities as 'surprising.' The company has also identified a recent social media spike in Washington, D.C., Philadelphia and New York City of protesters looking for rides to Baltimore, suggesting that the situation may not be over just yet. Baltimore's mayor, Stephanie Rawlings-Blake, announced a 10 p.m.- 5 a.m. curfew would be imposed beginning on Tuesday. The use of social media to fuel violence in Baltimore has already been highlighted by law enforcement. Missouri State Highway Patrol officers listen to taunts from demonstrators during a protest over the death of Michael Williams last August  in Ferguson: Social media experts have linked the presence of 'professional protesters' or anarchists to both events . In the hours before Baltimore erupted into riots on Monday, an online flier swept across social media inciting high school students in the area to 'Purge' - a reference to a movie, starring Ethan Hawke, where all crime is made legal. Police said on Tuesday that 202 people were arrested, 15 buildings set on fire along with 115 vehicles. Gray, 25, was arrested for possession of a knife on April 12 on Baltimore's west side. According to his attorney, Gray died a week later in hospital from a spinal cord injury he received in police custody. As Gray's grieving family held his funeral on Monday morning, an online flier circulated among school students, reading: '@3 We Going To Purge', beginning at Mondawmin Mall in the northwest of the city and moving downtown. 'The Purge': A flier (pictured) circulated online on Monday calling for a 'purge' prior to the rioting and looting which took place on the day that Freddie Gray, a 25-year-old who died in police custody, was laid to rest . Young people pelted police with rocks on Monday in Baltimore following an online flier which circulated calling for a 'purge' - an apparent reference to a 2013 movie where all crime is legalized . On the flier was an image of young men jumping on top of a police car on Saturday during protests, The Baltimore Sun reported. The word 'purge' appeared to reference a 2013 sci-fi horror movie, The Purge, which depicted a futuristic world where for a 12-hour period, all crime is legalized. The film, starring Ethan Hawke and Lena Headey, and directed by James DeMonaco, had a sequel last year - The Purge: Anarchy. It is unclear whether police were investigating the origins of the social media flier. As the message spread across social media, law enforcement mobilized troops while businesses rolled down their shutters and the University of Maryland canceled classes. Around 3pm on Tuesday, news cameras caught live scenes as dozens of students descended on Mondawmin Mall where they were greeted by lines of police officers, wearing riot gear, carrying shields and armed with pepper spray. Police were pelted with rocks, water bottles and anything that came to hand. As the sun rose on Baltimore's Eastside on Tuesday, the remains of a Baptist Church's senior center were still smoldering after being set ablaze during night riots . Fifteen police officers were injured, many suffering broken bones, and at least one appeared 'unresponsive'.  Two of the 15 cops were hospitalized in a serious condition. A $16 million nursing home built by a Baptist church, which was due to open in December after eight years of construction,was burned to the ground on the city's east side as violence from corner to corner of Baltimore. Just two blocks away from the nursing home, a housing development was also ablaze. According to Baltimore Police, cinder blocks were being thrown at fire trucks as they raced to extinguish the blazes and one protester was caught on camera sticking a knife into a hose. Officials feared the fires were sparked to pull emergency services from the west side of the city, where rioters continued to loot gun stores, check-cashing stores, liquor stores and supermarkets into the early hours of Tuesday. Balaclava-clad mobs were seen ripping the doors off one rifle shop and passing weapons to people on the streets. A senior center and a CVS pharmacy burned to the ground in Baltimore on Monday night as the family of Freddie Gray called for calm on the day of his funeral . One of the buildings set on fire amid riots which broke out on Monday in Baltimore leading to widespread rioting and looting which left 15 police officers injured . When a CVS pharmacy was set ablaze, rioters slashed fire fighters' hoses as they tried to battle the flames. Small stores including a 'mom-and-pop' grocery store and a local hair salon were also looted, The Baltimore Sun reported. The Gray family has publicly denounced the riots and called again for peace on Monday. Bill Murphy, the family's attorney, branded the situation 'devastating', adding: 'This won't solve the police problem. This is dangerous to the movement.' 'I think the violence is wrong,' Gray's twin sister, Fredericka Gray, said late on Monday. 'I don't like it at all.' On Tuesday, social media rumors of another 'purge' led Security Square Mall - five miles from where yesterday's riots took place - to close its doors, The Baltimore Sun reported. Medicaid and Medicare facilities were also shut in Baltimore County and some federal staff were going home early. April 12: 8:39am: Four officers stop and arrest Freddie Gray (pictured right) who ran away from the police in northwest Baltimore after 'making eye contact'. 8:40am: Gray is arrested after voluntarily stopping. No police reported using their Taser. 8.42am: Officers held him down, handcuffed him and loaded him into a police van. While inside, he became irate and leg cuffs were put on him, police have said. 9am: Gray was not buckled in by a seat belt, a violation of the police department's policy. 9.26am: He asked for medical help several times, and after a 30-minute ride that included three stops, paramedics were called. At some point - either during his arrest or inside the van - he suffered a mysterious spinal injury. Authorities have not explained how or when it occurred. April 19: Freddie Gray died from a double broken vertebrae after being arrested near Gilmor Homes in Sandtown-Winchester. It is reported his spine is 80 percent separated from his neck. Deputy police commissioner Kevin Davis said Friday that Gray should have received medical attention at the spot of his arrest. April 27: Freddie Gray's family and 2,500 mourners attended his funeral at the New Shiloh Baptist Church. 3pm: Riots break out on the Westside of Baltimore and mushroom across the city after a flier is circulated online calling for a 'purge'. Gray's grieving family call again for peace saying violence was not what their son would have wanted.
Data mining firm has found between 20 and 50 social media accounts active in Baltimore on Monday were also used in Ferguson last summer.
Link suggests the presence of 'professional protesters' or anarchists who looking to take advantage of Freddie Gray's death to incite more violence.
One account  tweeted photos of Gray's funeral and used language anticipating Monday's violent clashes.
A 10 p.m.- 5 a.m. curfew has been imposed by the mayor of Baltimore.