Philippine soldiers killed 10 Islamic rebels in fresh fighting in the south on Thursday as President Gloria Macapagal Arroyo vowed to put down the militants "with a hand of steel".
Lieutenant-Colonel Ariel Caculitan, a Marine spokesman, said 10 Abu Sayyaf militants and three soldiers were killed in a hour-long gunbattle on the island of Jolo, where most of the militant group has taken shelter. Two rebels were captured.
About 100 United States military advisers are on Jolo to provide intelligence and training to the 7,000 Philippine troops combating the Abu Sayyaf, the most deadly militant group in the country.
The group, allied to the regional Jemaah Islamiah, is accused of deadly bomb attacks and kidnapping and beheading tourists, including Westerners.
It was the latest success reported by the military against Abu Sayyaf. On Wednesday, troops claimed they had killed Jainal Antel Sali, alias Abu Sulaiman, one of the top five leaders of the group in a gunbattle at a jungle camp on Jolo.
A number of other Abu Sayyaf senior commanders have been killed in recent weeks, including Binang Sali, considered to be one of the group's spiritual leaders.
"It's not the end-game but it will take the sting out of their tail," said a Western diplomat of the string of military successes.
"It's breaking down their capacity to function as a group and concentrate on attacks, but the Abu Sayyaf will continue to exist in some form or another."
Arroyo met senior army commanders at the main military camp in Manila to commend them for the killing of Abu Sulaiman.
"This government is determined to finish the job with a hand of steel against evil," Arroyo said in a statement.
"The relentless pressure we have applied in the field is taking its toll and we will keep it up until all terrorists and their clandestine cells are accounted for."
The military said the pressure on the group would continue.
"Right now, they are suffering from a leadership vacuum and they are now disorganised," said Lieutenant-Colonel Bartolome Bacarro. "We will keep up the tempo.
"We cannot give you a timeframe but the armed forces of the Philippines, by direction of the president is really bent on destroying the Abu Sayyaf group."
Abu Sayyaf has only 400 or so members, most of them trapped on Jolo island, but it has been held responsible for the Philippines' worst terrorist attack, the bombing of a ferry near Manila Bay in 2004 that killed at least 100 people.