US-led coalition air strikes kill 27 in Raqqa

US-led coalition strikes killed 27 civilians in part of Syria's Raqqa city held by the Islamic State group, the Syrian Observatory for Human Rights monitor said on Monday.

Seven children were among the dead in the strikes on Sunday that "hit the densely-populated Al-Badu area in the centre of the city," Observatory director Rami Abdel Rahman said.

Once a militant stronghold, more than half of Raqqa city has fallen to the Syrian Democratic Forces, an alliance of Kurdish and Arab fighters that entered the city in June.

The SDF is heavily backed by the US-led coalition, which has regularly launched air strikes against the militants.

According to the Britain-based Observatory, at least 125 civilians have been killed in a week of US-led strikes on Raqqa city, including those who died on Sunday.

"There are civilians killed each day in coalition strikes... The closer the fighting gets to the densely-populated city centre, the more civilian deaths there are," Abdel Rahman said.

The coalition, which operates in both Syria and neighbouring Iraq, says it takes all possible measures to avoid civilian casualties.

In August, it acknowledged the deaths of 624 civilians in its strikes in Syria and Iraq since 2014, but rights groups say the number is much higher.

The UN's humanitarian chief for Syria, Jan Egeland, has said IS-held territory in Raqqa city is now "the worst place" in the war-torn country.

Last week, the Observatory reported 59 civilian deaths in three days from coalition strikes.

The UN estimates there are up to 25,000 civilians trapped inside the city, with food and fuel supplies short and prohibitively expensive. Islamic State reportedly forbids civilians from leaving.

Tens of thousands of civilians have also fled the city, risking IS sniper fire and landmines in the process. Many have fled to SDF-held territory, reports Reuters.

"When we got to the main road, bullets from Islamic State militants started flying by - they were trying to stop us leaving. The Syrian Democratic Forces started firing back, so we managed to run to SDF territory," said Omar, 57, whose family left their home after an air strike hit their neighbour’s home.

The SDF reportedly rescued 10 civilians on Monday in the Mansour neighbourhood in East Raqqa, ANF news announced.

The Russian Ministry of Defence also released a statement on Monday stating that over 200 militants were killed in air strikes on Deir Ezzor by the Russian air force. The statement said Russian jets targeted IS vehicles retreating in the city and a video appeared to show the strikes.

Over 330,000 people have been killed in Syria since the conflict erupted in March 2011 after anti-government protests.