A Philippine official says nearly 500 police launched simultaneous raids on drug dens and other criminal hideouts in a southern city, killing seven suspects and arresting 39 others in an ongoing anti-crime crackdown.

Police Director Benjamin Magalong said the seven men were killed in separate clashes Wednesday that erupted when they fired at police serving search warrants across Davao city. He said at least four syndicates involved in drug trafficking, killings and robberies were broken up.

Magalong said about 480 policemen spread out at dawn to serve 35 search and arrest warrants in one of the largest single-day anti-crime operations in the Philippines this year.

Violent crimes are a concern in the Philippines, along with kidnappings for ransom and banditry by al-Qaida-linked militants in the south.