A hostage drama that unfolded at a primary school in the southern Philippines on Wednesday has been resolved, a military spokesman said, and the Islamist militants who had held people captive had withdrawn with no reports of casualties.

"It's already resolved," Brigadier General Restituto Padilla told reporters. "They've withdrawn, they are no longer there. The school area is again safe."

However, 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.

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.