MANILA (Reuters) -- A battle pitting Philippine troops against Muslim guerrillas on a remote southern island killed at least 53 people, the military has said, but analysts said the clash is unlikely to have sidelined the rebels.
Soldiers killed at least 30 guerrillas during an assault on August 12 on a base of Abu Sayyaf rebels in the interior of the southern island of Basilan, Brigadier General Rustico Guerrero, marine commander, told reporters.
"Based on this one incident alone, it would be premature to make a conclusion on the neutralisation of the Abu Sayyaf," Mars Buan, an analyst at the Pacific Strategies and Assessments risk consultancy, told Reuters.
"In the past, the Abu Sayyaf has suffered bigger number of casualties, but it has remained as one of the serious threats in the south."
Twenty-three soldiers were killed and 20 were wounded in eight hours of fighting, Guerrero said, describing it as one of the biggest battles since 2007, when 15 soldiers and 40 rebels were killed on Basilan.
"We launched a decisive law enforcement operation targetting the Abu Sayyaf's main training base on Basilan, but we were met by heavy resistance," he said.
The guerrillas fled into the island's heavily wooded interior, said Rear Admiral Alexander Pama, navy commander on Basilan. Security forces on August 13 resumed pursuit operations against remnants of the 150-man rebel group.
"It was close quarter combat, the two sides almost came into hand-to-hand battle," Pama told Reuters. He said the proximity meant the military could not call in air strikes.
"What's more important for us was we've disrupted their crude bomb factory and training base."
Analysts expected intenwified operations against the Abu Sayyaf, but foresaw no decisive development in the conflict.
Buan said the Abu Sayyaf's loose structure meant an encounter on Basilan would not affect militants on nearly Jolo island.
Rex Robles, a retired navy commodore and a security analyst, said the rebels were both familiar with the territory and enjoyed the support of the local community.
"There are so many armed groups operating there, not just the Abu Sayyaf," Robles said. "I would not be surprised if some rogue members of the Moro Islamic Liberation Front come to the aid of the Abu Sayyaf. Some of them are related by blood and marriage."
The Abu Sayyaf is the smallest but most deadly of several Muslim groups fighting for independence in the south of the Roman Catholic state. It is estimated to have about 350 hard-core followers based mostly on Basilan and Jolo.
It has links with Jemaah Islamiah, a pan-Asian radical Muslim group blamed for attacks in Indonesia, including the 2002 Bali bombings and the bombings of two hotels in Jakarta last month.
Abu Sayyaf is blamed for the worst militant attack in the Philippines, the sinking of a ferry in Manila Bay in 2004 in which 100 people were killed.
It has also been in the spotlight for high-profile kidnappings, most recently of three Red Cross officials on Jolo who were later freed. Newspapers said large ransoms were paid, although officials have denied making any payments.