A car bomb has killed at least 51 people in a rebel-held village near the Syrian town of al-Bab, sources in the region and monitors say.
The blast - claimed by Islamic State (IS) militants - destroyed a rebel post in Sousian, said the Syrian Observatory for Human Rights, a monitoring group.
The village is 8km (five miles) north-west of al-Bab, from which Turkish-backed rebels drove out IS on Thursday.
Turkey says the rebels now have "control of all neighbourhoods" there.
"Activities continue to clear areas under control of obstacles, mines and hand-made explosives," the country's military said.
IS claimed the car bomb attack, in a statement carried by its Amaq news outlet.
Many civilians were gathering to seek permission to return to al-Bab when the bomb exploded, the opposition-run Qasioun news agency said.
Situated just north-east of Aleppo, al-Bab has about 100,000 inhabitants in the centre and about 50,000 more living in the suburbs.
It fell to Syrian rebels in spring 2012 and was in IS hands by early 2014, when it became home to many foreign jihadists and their families.
Gen Hulusi Akar, Turkey's chief of staff, told troops on Friday that with the seizure of al-Bab, Turkey's incursion into northern Syria had achieved its objective.
"In the aftermath, support will be provided to normalise life and for the local people to quickly return to their homes," he said.
The rebels say they are now working to clear the heavily mined town.
Turkish President Recep Tayyip Erdogan said last year that the capture of al-Bab, the jihadist group's last major stronghold in Aleppo province, would be the prelude to taking Raqqa, seen by IS as its capital in Syria.