A man threw a gas bomb into a crowded visitors' lobby in Sofia's central traffic police office today, injuring at least 40 people.
Bulgarian Health Ministry officials said the bomb contained a chlorine-based toxic gas, which causes tears, cough and suffocation.
The life of one of the injured people was in danger and at least four others were reported in critical condition.
The attack was at the traffic police office for public services, which at the time was crowded with people. The building was immediately evacuated. Two hours after the attack, police arrested a 51-year old man.