ZAMBOANGA (Philippines) - A SUSPECTED bomber was killed and four other people, including two policemen, were wounded in two explosions in the southern Philippines, the military said on Wednesday.

A man transporting an improvised explosive device was killed when it went off at a police checkpoint near the town of Esperanza on Mindanao island late on Tuesday, said regional military spokesman Lieutenant-Colonel Julieto Ando.

One police officer was wounded when the device made out of a mortar shell and hidden in a sack of charcoal detonated, Col Ando told reporters.

'The bomb was in transit and probably exploded due to faulty assembly,' he added.

Meanwhile, a policeman and two other people were wounded late on Tuesday when unidentified men tossed a bomb at a police outpost on the outskirts of General Santos city, the spokesman said.

Moro Islamic Liberation Front separatist rebels operating in the region denied any involvement in the Esperanza bombing. -- AFP