Picture: geralt/Pixabay

Manila - A Dutch man held captive for more than seven years in the southern Philippines was killed on Friday by his Islamist militant kidnappers while trying to escape, the military said.

Soldiers recovered the body of Ewold Horn after a firefight with Abu Sayyaf militants in Patikul town on Jolo island, 1,000 kilometres south of Manila, Brigadier General Divino Rey Pabayo Jr said.

"Horn was shot by his Abu Sayyaf guards while trying to escape, taking advantage of the firefight," said Pabayo, commander of an anti-terrorism task force in Jolo.

Six militants were killed in the clash, including a female member identified as the second wife of senior Abu Sayyaf leader Radulan Sahiron, he added.

Horn was abducted with Swiss man Lorenzo Vinciguerra and their Filipino guide on February 1, 2012 while on a bird-watching trip in the Philippines' southern-most province of Tawi-Tawi.

The Filipino guide escaped while they were being transported to Jolo, while Vinciguerra escaped two years later in 2014.

Horn was the longest-held captive of the Abu Sayyaf, which has been blamed for some of the worst terrorist attacks in the Philippines as well as high-profile kidnappings of foreign hostages.