A Philippine general says 23 soldiers have been killed in fierce clashes that also left at least 20 Al Qaeda-linked militants dead in the country's restive south.

Regional military commander Maj. Gen. Benjamin Dolorfino says about 400 army, marines and police commandos launched simultaneous, pre-dawn attacks Wednesday on two Abu Sayyaf extremist group encampments on Basilan Island, sparking fierce fighting that continued to rage late in the day.

Dolorfino said Thursday that 20 marines and 3 army men, including two officers were killed in the clashes.

Military officials say troops targeted Abu Sayyaf chieftains Khair Mundus and Furuji Indama, but it was not immediately clear if they were among the slain militants.