MANILA, Sept. 3 (Xinhua) -- The death toll in the powerful blast that rocked a southern Philippine town on Sunday night has risen to two, police said on Monday.

Provincial police chief Noel Kinazo of Sultan Kudarat province said a 15-year-old girl who was among the 15 people wounded in the blast died at the hospital on Monday morning.

On Sunday night, an 18-year-old boy died at the scene when an improvised explosive device ripped through an internet cafe in Isulan, a town in Sultan Kudarat province on Mindanao, around 7:35 p.m. local time.

This is the second blast within a week. On Aug. 28, a homemade bomb exploded the town killing three and injuring more than 30 others.

Sunday's explosion occurred some 500 meters from the site of the Aug. 28 explosion, police said.

No group has claimed responsibility for the two bombings.

The military pinned the blame for attacks on the Bangsamoro Islamic Freedom Fighters (BIFF), a spin-off of Moro Islamic Liberation Front (MILF) that forged a peace pact with the government.

The BIFF denied the accusations.