Syrians trapped in IS-held Raqqa at risk from airstrikes as SDF drive deeper into Raqqa

Syrian-Arab and Kurdish fighters have captured two districts to the west and east of the Islamic State group's self-declared capital Raqqa, as a multi-front offensive on the city intensifies. 

Syrian Democratic Forces (SDF) drove into Raqqa for the first time earlier this week, with fresh gains on Friday capturing al-Meshleb to the east of the city and al-Sabahia to the west.

It comes as the anti-IS force came under criticism after the US-led coalition launched banned white phosphorus into the city.

Advances

Heavy air strikes have helped the anti-IS force take parts of Jazra suburb which lies just to the west of Raqqa's city limits on Friday, the Syrian Observatory for Human Rights reported.

Heavy clashes broke out in other parts of the city with SDF spokesman Talal Sello saying the fighters have advanced on several fronts on Friday.

"The SDF has control of al-Meshleb district and is clearing it of mines and explosives at the moment," he told AFP.

SDF forces had also advanced on the northern front outside the city, he said.

At least 15 civilians were killed in an air strike on an internet cafe, while at least eight more died in two dozen US air raids.

Four local journalists were also injured when an IS mortar round landed near them as they made their way toward Meshleb.

Meanwhile white phosphorus attacks on Raqqa were reported for second night on Friday. 

The SDF are expected to move from Meshleb into neighbouring al-Senaa, with the area in between being targeted by the US-coalition overnight, the Syrian Observatory for Human Rights said.

Although its believed many IS fighters have fled the city others have dug in with booby-traps, tunnels and snipers positioned to slow the SDF advance.

Civilians in peril

It is estimated by Washington that 2,500 IS fighters remain in Raqqa.

Around 300,000 civilians were believed to have been living under IS rule in Raqqa, although thousands have fled in recent months leaving 160,000 in the city according to the UN.

UNICEF warned "an estimated 40,000 children remain trapped in dangerous conditions in Raqqa city".

"Many are caught in the crossfire," said UNICEF regional director Geert Cappelaere, according to AFP.

The anti-IS coalition have dropped leaflets on Raqqa, instructing civilians on how to flee the city safely.

One leaflet dropped could potentially endanger the lives of civilians following the instructions, telling people to head towards the SDF frontlines which could be a potentially deadly mistake given the likely extreme suspicion and nerves among the fighters.

Since the offensive was launched on the city, the leaflets now warn civilians to stay at home leading to confusion about the safest option for families, Air Wars reported.

If civilians flee they also face the risk minefields and bullets from IS militants.

Analysts believe the anti-IS coalition will allow militants to flee the city to reduce the damage to Raqqa and harm to its civilian population.

Agencies contributed to this story.