Government forces have seized a strategic town in eastern Syria, part of an ongoing offensive against Kurdish-led Syrian Democratic Forces (SDF) east of the Euphrates River.

The rapid army operation on Sunday follows battles earlier this month between Damascus and the United States-backed SDF, which led to deadly clashes and the government taking control of three neighbourhoods in Aleppo city from the group.

Sunday’s advance into Tabqa, in Raqqa province, is seen as critical because of a nearby dam that regulates the southward flow of water into areas held by the SDF.

The government and the SDF have exchanged accusations of violating a March agreement intended to reintegrate northeastern Syria and Kurdish-led forces into the structures of the Syrian state.

The SDF controls large swathes of northeastern Syria and has for years been Washington’s key ally in combating the ISIL (ISIS) group. Over that period, the US has developed strong ties with the SDF and has tried to ease tensions between the two sides.

The US had urged calm after this month’s clashes in Aleppo killed 23 people and displaced tens of thousands. After the fighting subsided, SDF leader Mazloum Abdi (also known as Mazloum Kobani) said on Friday that the group would withdraw its forces from areas east of the Euphrates following an announcement by Syrian official al-Sharaa on measures to strengthen Kurdish rights in Syria.

Tabqa is the latest in a series of mostly Arab-majority areas captured by government forces in Raqqa province. It remains unclear how far into the Kurdish heartland the Syrian military intends to advance.

Meanwhile, the Syrian government has accused the SDF of executing prisoners in Tabqa before withdrawing.

The SDF has denied the allegation, saying it transferred detainees out of the prison and accusing government forces of firing on the facility.

The United Kingdom-based Syrian Observatory for Human Rights war monitor reported that government forces have taken control of more than a dozen villages and towns in the eastern Deir Az Zor countryside following the SDF withdrawal.