Philippine forces on Wednesday arrested a Muslim extremist believed to have taken part in the kidnapping of 21 people from a Malaysian resort in 2000, a senior commander said.

Such cross-border kidnappings have become more common recently with militants from the lawless southern Philippines traveling to nearby Malaysia, where there are many dive resorts popular with foreign tourists.

Suspected Islamic militants have freed a Filipino engineer they abducted in the southern Philippines 53 days ago, the military said Sunday.

Bonifacio Salinas was seized by alleged members of the Abu Sayyaf group on the volatile southern island of Jolo in February along with his wife, Claire, who was freed a month later.

The Philippines said Saturday it was stepping up its defenses against the deadly MERS virus, with the large numbers of Filipino workers in the Middle East seen as potential carriers.

"It is important that families, friends and members of their local communities fully understand all that must be known about the MERS coronavirus," Health Secretary Enrique Ona told a news conference.

Thousands of people flocked to rural fields in the Philippines on Friday to witness the gruesome spectacle of men being crucified in their annual Easter re-enactment of the death of Jesus Christ.

The ritual, held every year to mark Good Friday in Asia's bastion of Catholicism, has been going on for decades, becoming a major tourist draw despite official disapproval from Church leaders.

The Philippines' largest Muslim rebel group on Tuesday denounced the killing of four of its members in clashes with soldiers, just two weeks after a peace deal was signed to end their decades-old conflict.

The military has acknowledged that gunmen from the Moro Islamic Liberation Front (MILF) were among 20 people killed in a shootout on a remote southern island Friday as security forces pursued Islamic militants blamed for beheadings and kidnappings.

Philippine President Benigno Aquino on Monday formally received a draft law representing a crucial step towards the creation of an autonomous area for the country's Muslim minority, following a historic peace deal.

Aquino received the Bangsamoro Basic Law from a special transition committee headed by representatives of the Moro Islamic Liberation Front (MILF), once the main Muslim rebel group in the majority-Catholic Philippines, his aides said.

Police commandos stormed a southern Philippine hideout of suspected Abu Sayyaf extremists blamed for kidnappings and extortion, triggering a firefight that led to the killing of two militants and the capture of six others, officials said.

Chief Superintendent Getulio Napenas, director of the national police Special Action Force, said his men raided a house Monday in Zamboanga City where an Abu Sayyaf sub-leader and his followers were believed hiding.

A Muslim extremist has been killed in fighting between soldiers and Abu Sayyaf rebels in the southern Philippines, a day after 12 people died in a similar shootout, the military said Sunday.

Troops in the strife-torn island of Jolo were on patrol when they clashed with the Islamist guerrillas on Saturday, said military spokesman Lieutenant Colonel Romeo Zagala.

The death toll in fighting between Muslim rebels and soldiers in the southern Philippines has risen to 12, officials in the area said Saturday after the prolonged shootout had ended.

Government forces launched the operation Friday to capture two top leaders of the al-Qaida-linked Abu Sayyaf group blamed for beheadings and kidnappings, but failed to apprehend either man.

The Philippines said Friday it hopes to complete a new defense accord with the United States ahead of a visit by President Barack Obama this month, as a territorial dispute with China simmers.

The chief Philippine negotiator, defense undersecretary Pio Lorenzo Batino, said in a statement the latest round of discussions about an increased U.S. military presence in the country was "very productive."