At least 20 civilians, including some children, have been killed in suspected US-led coalition air strikes on a village east of Islamic State's de facto capital in Syria, activists reported.
The report comes as the militants come under mounting pressure from rival US-backed and Russian-backed forces working to seize Raqqa.
Also on Thursday, engineers restored two water pumping stations that feed water to the country's largest city, Aleppo, in territory captured by the Syrian government from IS militants this week, state media reported.
Aleppo, once Syria's industrial capital, suffered for years from severe water shortages as the government and opposition fighters contested the city and IS controlled its upstream source - the pumping stations at the town of Khafseh on the Euphrates River.
Pro-government forces defeated the rebels in the city just before the new year and took Khafseh from IS militants earlier this week.
Residents in Aleppo have depended on wells and water deliveries arranged by the government, charities and the UN children's agency Unicef.
Imad al-Khal, 64, a resident of the al-Aziziyeh neighbourhood in Aleppo, told the Associated Press that municipal water has not reached her home in nine weeks.
In the area east of Raqqa, the activist group Raqqa is Being Slaughtered Silently reported at least 20 civilians were killed in air strikes on Wednesday night on Matab Village.
The Britain-based Syrian Observatory for Human Rights, however, said the strikes occurred before dawn on Tuesday and killed 23 people, including eight children.
It was not possible to reconcile the two accounts - IS maintains a tight grip on communications from its territory. The observatory and RBSS get their information from closely guarded local contacts.
Russian and Syrian aircraft are not known to operate in the area, according to the observatory.
The group said US-led coalition aircraft were believed to be behind the attack.
The coalition did not confirm the strikes and there was no immediate indication which nation's aircraft were involved.
US officials said on Wednesday that a few hundred marines have deployed into Syria with heavy artillery guns as part of preparations for the fight to oust IS from Raqqa.