French cops at the entrance to Notre-Dame cathedral. Pic/AFP

A man armed with a hammer shouted "this is for Syria" before attacking police officers on Tuesday outside France's Notre Dame cathedral in Paris, the interior minister said. The assailant wounded one officer before he was shot and wounded by other officers. The Paris prosecutor's office swiftly began a counter-terrorism investigation. Interior Minister Gerard Collomb said the attacker was carrying the identification card of an Algerian student.