import re


def extract_accident_time(text):
    """
    extract accident's time from tweet text
    :param text: tweet text
    :return: extracted accident's time
    """
    reg_exp = r'בשעה (\d{2}:\d{2})'
    time_search = re.search(reg_exp, text)
    if time_search:
        return time_search.group(1)
    return None