Militants fighting in the name of the So-called "Islamic State" (ISIS , ISIL , IS or Daesh) group are escalating attacks in the southern Philippines, deepening fears for the volatile region after its main rebel group failed to seal a peace pact.

Gunmen who have pledged allegiance to the ISIS terrorists controlling parts of Iraq and Syria have instigated a series of deadly battles with the army since last month.

The clashes are continuing. AFP video footage shows rockets being fired from an army helicopter, as well as troops in a cornfield firing mortars and carrying a wounded solider on an improvised stretcher.

More attacks could be expected from other groups that have publicly pledged allegiance to ISIS in Internet videos over recent years.

These include the Abu Sayyaf, a group notorious for kidnapping foreigners.

The violence has over the decades mainly been restricted to the south, many hundreds of kilometers from the Philippine capital.

Abu Sayyaf bombed a ferry in Manila Bay in 2004, killing more than 100 people.