Hundreds of Islamic State-linked militants held children hostage at a primary school in the Philippines, according to reports.

About 300 armed men took the students captive on Wednesday morning when a gunfight with military broke out.

The school is in Pigcawayan in the North Cotabato province on Mindanaeo Island, where government troops and Islamists have been fighting for four weeks.

Some of the militants behind the hostage situation were members of the Bangsamoro Islamic Freedom Fighters (BIFF).

A military spokesman told AAP there were no reports of casualties and the hostage situation had been resolved.

“It’s already resolved,” Brigadier General Restituto Padilla said.

“They’ve withdrawn, they are no longer there. The school area is again safe.”

However, Mr Padilla also said the military was investigating whether five civilians were still being held by the militants.

He said no children had been taken hostage.

An army spokesperson said the militants took five people hostage as human shields when they escaped, Capt. Arvin Encinas told the Philippine Daily Inquirer.

Earlier, a spokesman for the militant group said they had taken civilians to a safe place after a gunfight erupted with troops and did not intend to hold them.

Eliseo Garcesa, mayor of Pigcawayan town, said he was seeking information about possible casualties.

– More to come