DAMASCUS, Oct. 3 (Xinhua) -- At least 45 civilians were killed on Tuesday by a U.S.-led airstrike on Islamic State (IS)-controlled areas in the northern city of Raqqa, local media said, as the Kurdish-led fighters say they are advancing in that city.

Children and women were among those killed in the airstrike by the U.S.-led anti-terror coalition, which targeted two residential buildings in the Tawasoiyeh area north of Raqqa, said pro-government al-Watan online daily.

The Syrian Observatory for Human Rights also reported the airstrike, saying 18 people were killed when the airstrike targeted water wells in the Tawasoiyeh area.

The attack is the latest in a series of airstrikes that have intensified recently by the U.S.-led coalition, in their latest push to control Raqqa with the help of the ground forces of the Kurdish-led Syrian Democratic Forces (SDF).

With their incessant airstrikes, civilian casualties have been increasing on daily basis.

Syria's Foreign Ministry renewed its condemnation Tuesday of the U.S.-led airstrikes.

In letters sent to the UN, the ministry urged the international community to stop the "crimes" of the U.S.-led coalition.

It said the coalition has committed massacres in Raqqa and Deir al-Zour over the past two days, killing 57 civilians.

The ministry charged that the U.S. is hindering the progress of the Syrian army in the eastern province of Deir al-Zour to prevent the government forces from capturing areas under IS control, "which exposes the real intention behind the destructive U.S. policy in Syria."

The ministry again urged the UN to dissolve the coalition, saying its operations in Syria are illegitimate.

On the ground in Raqqa, the U.S.-backed SDF said Tuesday its fighters have captured a main command center of IS.

And 22 IS militants have been killed over the past two days during the battles in Raqqa, the SDF added.

Meanwhile, the group said that the local council of Raqqa met with "international representatives" to discuss the future of Raqqa after the defeat of IS.

The group, however, has stopped short of giving further details on the meeting and the figures that have taken part in it.

Activists has recently said that the SDF are closing in on IS in Raqqa, with the observatory saying the Kurdish-led fighters are controlling over 90 percent of the city of Raqqa.