Gunmen have ambushed a campaign vehicle of a southern Philippine town mayor, killing at least 10 people, including his daughter and relatives, while they were returning from an election rally, police have said.



Officials confirmed the death toll on Friday from the attack that took place late on Thursday when gunmen opened fire on a truck carrying Mayor Abdulmalik Manamparan and his supporters on southern Mindanao island.



About 15 unidentified gunmen carried out the attack, Lanao del Norte provincial police chief Gerardo Rosales said. Police investigators suspect the gunmen belong to a rival clan.



The ambush on a remote mountain road near Nunungan town, unleashed as the mayor and his supporters travelled home from a campaign event, was the latest episode of political violence in the Philippines which will hold local elections on May 13.



Local military commander Colonel Ricardo Jalad said several victims were relatives of the Nunungan mayor, who was also wounded in the attack along with seven supporters.



"They killed my granddaughter," Manamparan said, from his hospital bed, where the 62-year-old official was being treated for a shrapnel wound that grazed his head.



Deadly elections

A running police tally lists 30 deaths from 45 other violent incidents reported since the start of the campaign in February.

Election season violence is common in the Philippines.

In November 2009, members of a powerful clan on Mindanao abducted and murdered 58 people including relatives of a local rival who was planning to challenge the clan leader in gubernatorial elections the following year.

Manamparan, of the opposition Nationalist People's Coalition party, is the mayor of the mainly Muslim town of Nunungan. He told AFP news agency that he had a good idea who was responsible for the attack, but declined to discuss his suspicions.

The predominantly Muslim areas of Mindanao have a reputation for deadly clan wars, sometimes lasting generations. The island is also wracked by insurgency waged by Muslim and communist rebels.

Manamparan is standing for the lower post of vice-mayor, with his son and namesake running for mayor.