Philippine security forces continue to make progress in an offensive to retake the besieged southern city of Marawi from ISIL-backed militants, a presidential spokesperson said on Wednesday.

Philippine troops continue to battle an estimated 100 militants who are holed up in some parts of the city as the siege enters its 23rd day.

"Troops continue to gain footholds into the inner areas of terrorist-held areas," presidential spokesperson Ernesto Abella said at the Malacanang presidential palace.

Soldiers driving through Marawi on the southern island of Mindanao, June 14, 2017. /VCG Photo

"Enemy resistance continues to dwindle and enemy-held areas are getting smaller as troops advance," he said.

Abella said that critical sectors in peripheral areas are now being cleared.

"Clearing operations continue to be positive, out of 96 (villages) only four remain problematic areas and where focused military operations in urban terrain is currently ongoing," he said.

Police officers at a checkpoint carry empty jerrycans on a street in Marawi on the southern island of Mindanao, June 14, 2017. /VCG Photo

However, Abella said there are obstacles hampering sealing operations. "Compounding development remains the use of civilians as human shields and mosques as safe havens," he said.

"This is where the problem lies," said Brig. Gen. Restituto Padilla, a military spokesman, referring to the difficulty troops face in operating in "urban terrain."

"In an urban terrain where civilians are still currently trapped and may possibly be used as human shields or may be hit by crossfire, troops have to be careful. We have to be very careful, we have to be very judicious, we have to be very deliberate so as to avoid hitting innocent lives," Padilla said.

Policemen and civilians are trapped in a militant-controlled area of Marawi.‍ This picture was taken on June 13, 2017 during a press conference in Marawi on the southern island of Mindanao. /VCG Photo

Padilla added, "And this is where the slow process of liberating Marawi is currently happening. So, it will entail a bit of time before we clear every house of any armed element."

Since militants attacked the city on May 23, the military said 290 people have been killed, including 206 militants, 58 soldiers and 26 civilians. The attack also prompted more than 200,000 residents to flee to nearby provinces.

But the military said there are still an estimated 300-600 civilians trapped in the city.

(Source: Xinhua)