MANILA, July 31 (Xinhua) -- Death toll of the vehicle bomb explosion in the southern Philippines island of Basilan on Tuesday increased to 10, according to military sources.

The sources said one solider, five militia men and four civilians were killed in the blast. The civilians killed include a mother and her child. A few others were injured in the attack.

The military said the Abu Sayyaf group, notorious for carrying out bombings and kidnapping, may have been behind the attack. The group is believed to have ties with the Islamic State radical group.

A military report said the attack occurred at 5:50 a.m. local time when a "white van" was detonated at a military checkpoint in Colonia village in Lamitan City on Basilan, an island province off Mindanao.

The military had previously put the death toll at six.