Abu Sayyaf gunmen on July 28 attacked Filipino civilians in two vans in the southern province of Sulu, killing 21, including six children.

Eleven others were also wounded in the attack, after the gunmen fired at the vans carrying the civilians to a celebration of the end of Ramadan festival, police and military officials said.

The motive was not clear, but some of the dead are said to belong to a civilian security force reportedly engaged in a clan feud with the Abu Sayyaf.

The Abu Sayyaf has about 300 armed fighters operating in the southern Philippines. The group is known to often seize hostages for money. It now holds about 10 hostages, including two German tourists seized in April, one Dutch and one Swiss, who were kidnapped two years ago.-VNA