MANILA (Reuters) - Philippine security forces have arrested three men suspected of being behind last month's deadly attack on a street market in the president's home city, and found they were linked to Islamic State militants, the defence minister said on Friday.
The suspects belonged to a radical faction of a Muslim rebel group and were arrested at a checkpoint while transporting improvised bombs, Delfin Lorenzana told a news conference.
A video had been recovered in which the suspects were "trying to align themselves" with Islamic State, he said.
"We have recovered solid pieces of evidence showing that they are indeed the terrorists who bombed Davao City," Lorenzana said.
The three men, wearing orange prison uniforms and handcuffs, were paraded before the media.
Fourteen people died and 70 others were wounded in the Sept. 2 bombing in Davao, the city which Rodrigo Duterte was mayor for 22 years prior to being elected president.
Duterte was at the time in Davao, where he typically spends his weekends, but was nowhere near the blast site.
Lorenzana said that attack was aimed to "disrupt and divert" the attention of the military from its campaign to wipe out the Islamist Abu Sayyaf group in the country's south.
"We are still looking for the mastermind," he said, adding there were 10 people involved and the group had prepared grenades as a backup plan if the bombs failed.
Firearms, ammunition and home-made bombs were discovered on Friday when security forces raided the house of the father of one of the arrested suspects in Mindanao province, Lorenzana said.
Reporting By Manuel Mogato; Editing by Martin Petty and Nick Macfie