The Philippine military says it has attacked an area where a local Muslim rebel leader and Indonesian militants are believed to have been hiding.
By Sarah Toms
Military helicopters and planes fired rockets and dropped bombs in the area, on the southern island of Mindanao.
Army officials could not confirm that they had killed any of the militants.
Officials say the main targets were the chief of the Abu Sayyaf rebel group, Gadafi Janjalani, and Indonesian members of Jemaah Islamiah.
Both organisations have been linked to the al-Qaeda network led by Osama Bin Laden.
The militants are thought to have been holding a meeting when security forces attacked.
The Indonesians in the group are believed to have included a man known as Dulmatin, who is alleged to have taken part in the Bali bombings in 2002.
Abu Sayyaf is a Philippine Muslim group known mainly for kidnappings and bombings against Christians and foreigners. Mindanao is also home to rebels from the Moro Islamic Liberation Front (MILF), the largest Muslim separatist group in the Philippines.
The military says rogue MILF rebels, who broke a 17-month truce by attacking an army outpost earlier this month, were also at the meeting.
Philippine officials say members of Jemaah Islamiah (JI) are being sheltered by some MILF commanders.
The MILF is due to restart peace talks with the government in February.
They have denied any formal ties with JI and say the recent attack on the army outpost was not sanctioned by rebel leaders.