Eleven Philippine soldiers were killed and seven others are injured in a "friendly fire" incident in the city of Marawi, defence officials said on Thursday. friendly fire is a term which means discharge of a military weapon that injures or kills a member of one's own armed force.
Brigadier General Restituto Padilla told the media that "the soldiers were killed and wounded in airstrikes aimed at Islamist militants on Wednesday", Xinhua news agency reported.
"One of our SF-260 aircraft was conducting an airstrike and accidentally it fired went wayward for an unknown reason and hit our own ground forces," Padilla said and then further added "Maybe the coordination was not properly done so we hit our own people. We don't know yet what exactly happened".
Defence Secretary Delfin Lorenzana said the military is sending more troops to Marawi to fight the remaining 50 to 100 extremists still holed up in the embattled city.
The ongoing clashes have so far killed over 90 militants, including at least eight foreign fighters, 19 civilians and 36 security personnel.
On May 23, heavily-armed militants attacked Marawi -- which has a population of about 200,000 people -- when the military was searching for an Abu Sayyaf leader hidden in the city.