MANILA, Philippines -- Security forces will intensify intelligence gathering as part of efforts to halt a fresh wave of attacks by renegade Moro Islamic Liberation Front (MILF) in Central Mindanao, a top adviser of President Gloria Macapagal-Arroyo said Monday.

At the same time, National Security Adviser Norberto Gonzales said the government was checking whether the mainstream MILF, which is negotiating peace with government, was involved in the attacks.

On Christmas Eve, MILF rogues attacked civilian communities in Senator Ninoy Aquino town, Sultan Kudarat province, killing at least seven people. The attacks continued until Sunday, with the rebels targeting villages in Sultan Kudarat and North Cotabato, according to reports.

"To stop these attacks, we will increase police and military activity. We will intensify our intelligence operation," Gonzales told radio station Radyo ng Bayan.

On reports that the mainstream MILF was involved in the fresh attacks, Gonzales said in Filipino: "We are studying that. MILF officials said they were not behind it... but it seems their members did it, that's why we're studying it carefully."

In August, MILF commanders Umbra Kato, Abdurahman Macapaar alias Bravo and Aleem Pangalian burned houses, killed civilians, and seized farm lands in the provinces of North Cotabato and Lanao del Norte, grounding formal peace negotiations to a halt.

The renegade commanders were protesting a Supreme Court ruling that the declared the Memorandum of Agreement on Ancestral Domain (MoA-AD) unconstitutional.

The MoA-AD would have paved the way for the expansion of the Autonomous Region in Muslim Mindanao (ARMM) into the Bangsamoro Juridical Entity (BJE).