Philippine police defused a bomb found in a rubbish bin near the US embassy in Manila Monday, authorities said.

The police chief of the national capital region told AFP an improvised explosive device composed of a cellphone, blasting cap, 9-volt battery and 81-millimetre mortar was found by a street sweeper about 200 meters from the embassy.

"Most probably there was an intention to bomb the area because there's a detonating device, a cellphone, but this is still under investigation," chief superintendent Oscar Albayalde said in a phone interview.

Police sent a team to "disintegrate" the device shortly after it was reported to authorities, Albayalde added.

Albayalde said police still had no suspect and were interviewing witnesses while seeking to obtain CCTV footage of the area.