Egypt's state news agency "MENA" says three policemen have been killed and four others injured when their car turned over while chasing a group of criminals in Sinai. MENA said Sunday the policemen had been chasing a group of armed criminals on the international road in central Sinai. MENA also said that a group of militants fired at a security checkpoint before escaping in Sheik Zweid on Saturday in northern Sinai. No casualties were reported.