MANILA (REUTERS) - Philippine troops have clashed with remnants of a pro-ISIS militant group that held a southern city for five months last year, the army said on Monday (June 18).

Colonel Romeo Brawner, the deputy commander of Joint Task Force Marawi, said security forces conducted air and ground assaults in the province of Lanao del Sur on Sunday in a bid to flush out Maute rebels and the group's new leader.

Col Brawner said he could not confirm if there had been any casualties in military operations in two towns near Marawi City, which is now undergoing rehabilitation with some residents returning to their homes.

The military was targetting Abu Dar, who the government believes is the new "emir" of the Islamic State in Iraq and Syria in South-east Asia, Col Brawner said. It could not be independently verified if ISIS has chosen Dar as its new leader in the region.

ISIS-inspired militants seized parts of the southern city of Marawi in May 2017, raising concerns about the influence of the extremist group in South-east Asia.

The army ended combat operations after wresting control in southern Marawi in October, and has shifted its focus to the island's marshes where other pro-ISIS militants operate.

The siege of Marawi, the country's biggest battle since World War II, displaced some 350,000 residents and more than 1,100 people were killed, mostly militants.

Military and security experts have said militants who escaped from Marawi are recruiting fighters using looted cash, gold and jewelry worth tens of millions of dollars.