At least 18 soldiers were killed in fierce day-long fighting with Abu Sayyaf extremists in the southern Philippines on Saturday in the largest single-day government combat loss this year

At least 18 soldiers were killed in fierce day-long fighting with Abu Sayyaf extremists in the southern Philippines on Saturday in the largest single-day government combat loss this year.

At least 52 other soldiers were wounded in the clashes with the Abu Sayyaf and its allied gunmen in the hinterlands bordering Tipo Tipo and Al-Barka towns on Basilan island, three military officials told AP. Four militants were killed in the clashes.

The large combat casualties were reported as the country marked the Day of Valor to remember Filipino veterans who perished in World War II.

Government forces were deployed to kill or capture Abu Sayyaf commander Isnilon Hapilon, who has publicly pledged allegiance to the Islamic State group and has been hunted for years for his alleged involvement in several terrorist attacks.

The militants, however, apparently managed to reinforce their ranks quickly and managed to muster between 100 and 150 fighters, allowing them to inflict large casualties on troops, the officials said.

It’s the largest single-day government combat loss this year in the south, where the military has been battling Muslim separatist rebels and extremists, and Marxist guerrillas.