By Hader Glang

ZAMBOANGA CITY, the Philippines

The Philippines armed forces says it has established a naval blockade around the predominantly Muslim island province of Sulu to prevent a Daesh-linked group it has been battling for two weeks from fleeing.

In a statement Thursday, Brig. Gen. Arnel dela Vega, commander of a joint task force battling the Abu Sayyaf, said the navy's newest and largest vessel had been deployed to the Sulu Sea in the country's south to lead the blockade.

President Rodrigo Duterte has ordered troops to destroy the group, with around 15 soldiers and 30 Abu Sayyaf killed in battles since the discovery of a severed head Aug. 24 belonging to a Philippines national kidnapped in Indanan town in Sulu -- an Abu Sayyaf stronghold.

Thousands of troops have subsequently been deployed to the jungles of Sulu and nearby Basilan for the offensive, some of them taking part in a battle in a mountainous part of Patikul town Monday in which the task force said a further two Abu Sayyaf had been killed.

On Thursday, Dela Vega underlined that the BRP Tarlac will serve as the command and control ship of the navy in its operations against the group and is preparing for any eventuality in case members of the group try to flee or they receive reinforcements from Basilan.

Duterte has placed the country under a “state of national emergency on account of lawless violence” following a bomb blast last Friday in Davao City that killed 14 people and wounded dozens of others.

Aside from the bombing, the declaration cited the ongoing offensive against the Abu Sayyaf and the beheading of hostages.

Since 1991, the Abu Sayyaf -- armed with mostly improvised explosive devices, mortars and automatic rifles -- has carried out bombings, kidnappings, assassinations and extortion in a self-determined fight for an independent province in the Philippines.

It is among two militant groups in the south who have pledged allegiance to Daesh, prompting fears during the stalling of a peace process between the government and the country's biggest Moro group that it could make inroads in a region torn by decades of armed conflict.