Security forces killed at least 40 civilians on Friday in attacks on demonstrations calling for international protection for Syria's pro-democracy protesters, activists said.

Most of the killings were in the main cities of Hama, where the security presence has been heavy since a military assault two months ago, and in Homs, where the army and militiamen loyal to President Bashar al-Assad have been raiding residential districts to put down protests and a nascent armed insurgency.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Louise Ireland)