MANILA (AFP) - Four people were arrested after a bomb was found in a van parked at Manila's international airport, authorities said on Monday.

The utility vehicle containing an "improvised explosive device" was found at the airport's terminal three car park at about 1.45 am local time (1745 GMT) on Monday, said a short report released by the National Bureau of Investigation.

"Four suspects were arrested," said the report, which was released by the airport's media affairs office.

The report gave no other details, and did not identify the suspects or say if the bomb had been safely dealt with.

The terminal, which for many years served only domestic flights but recently also began hosting international airlines, was operating as normal on Monday morning.

Airport spokespeople declined to comment.