MANILA, April 30 (Reuters) - At least 15 people were killed when security forces and Islamist militants exchanged mortar fire for three hours on Tuesday in a remote southern Philippine island, a marine general said on Wednesday, claiming the rebels were trying to retake their base.
Brigadier-General Martin Pinto said a soldier was killed and 19 others were wounded as sporadic fighting continued early on Wednesday in Patikul, Sulu, a known hotbed of the al Qaeda-linked Abu Sayyaf Group.
"By employing combined arms of 105mm howitzers, 81mm mortars and close air support from the MG520 helicopters, the marines were able to inflict heavy casualties on the enemy," Pinto told reporters.
"The wounded marines, most of them are caused by mortar shelling from the Abu Sayyaf, were evacuated to an army hospital for treatment."
Pinto said about 300 rebels launched an offensive to retake their base in Patikul after soldiers captured them on Monday.
"Our troops held their ground for three hours and repulsed the attack as reinforcement came," he added.
Early this month, security forces killed 18 Abu Sayyaf in nearby Basilan island as the Philippines stepped up an offensive against armed groups opposed to the peace pact with a larger Muslim rebel group, Moro Islamic Liberation Front (MILF).
The peace deal struck with the MILF ended a 45-year conflict that has killed more than 120,000 people, displaced 2 million and stunted growth in one of the resource-rich areas in the poor Southeast Asian state.
The situation on the ground remained shaky as other groups, particularly the Abu Sayyaf, a group on the U.S. anti-terrorist "blacklist", continued to pursue the armed struggle to set up a separate and independent Islamist state in the south.
Under the agreement, the rebels promised to disband their army, lay down their weapons and rebuild communities in exchange for an autonomous government with greater power over the economy and culture. The peace deal was brokered by Malaysia. (Reporting By Manuel Mogato; Editing by Michael Perry)