Officials say Philippine troops, backed by airstrikes and artillery fire, have killed several militants aligned with the Islamic State group in a new offensive in the marshy heartland of the country's south.

Army Maj. Gen. Cirilito Sobejana says several key militant commanders, including a long-wanted Singaporean, were among the more than 100 militants who came under attack Monday near Shariff Saydona Mustapha town in Maguindanao province. One soldier was killed and seven others were wounded in the firefight.

Sobejana said Tuesday that troops were checking if Singaporean militant Muhamad Ali Abdul Rahiman, who is also known as Muawiya, along with local commander Esmael Abdulmalik and bomb-maker Salahudin Hassan were among the wounded or slain militants.