Abu Sayyaf gunmen opened fire on the vehicles in Talipao town before dawn in what appeared to be an ambush related to a clan feud, said local marine commander Brig-General Martin Pinto.
“There were civilians as well as children among the 16 dead,” he told reporters, without giving more details immediately about those who died.
A number of policemen were riding aboard the two vehicles, he added, although he did not say if they were among the dead.
The Abu Sayyaf was founded in the 1990s with seed money from Osama bin Laden’s al-Qaeda network, and is blamed for the worst terrorist attacks in the Philippines’ recent history.
These include the 2004 bombing of a ferry that left more than 100 dead, abductions of foreign missionaries and tourists, and beheadings mostly of local people.