Turkey says it has killed 25 "terrorists" in Syria, shortly after a monitoring group reported dozens of deaths on the fifth day of a Turkish military offensive against the Islamic State of Iraq and the Levant (ISIL) group and Kurdish forces in northern Syria.
The Syrian Observatory for Human Rights (SOHR) said at least 20 civilians were killed and 25 wounded near al-Amarneh, while 20 people died in Jeb al-Kussa, outside Jarablus, on Sunday.
The village of al-Amarneh was captured by Turkish-backed Syrian rebels from Kurdish fighters as part of the military offensive. Jeb el-Kussa is located 14km south of Jarablus and is controlled by fighters from the area backed by Kurdish forces.
The monitor also said at least four Kurdish fighters had been killed and 15 injured in Turkish bombardment of the two areas.
Citing military sources, however, Turkey's state-run Anadolu Agency said a total of 25 fighters of the outlawed Kurdistan Workers' Party (PKK) and the Syrian Kurdish People's Protection Units (YPG) were "neutralised" in an air operation in Syria.
ANALYSIS - Kurds and refugees behind Turkey's Syria offensive
In a statement, the Turkish armed forces said the air campaign was carried out against "terrorist groups" which had attacked Turkish soldiers supporting a Free Syrian Army (FSA) operation in Jarablus.
"Five buildings used by the terrorists were also destroyed," the military said.
Earlier on Sunday, SOHR reported the civilian death toll of the operation near al-Amarneh and  Jeb al-Kussa was 35.
Jarablus, a former ISIL stronghold, was captured by the rebels on the first day of the Turkish operation.
Sunday's deaths came a day after Turkey blamed Kurdish forces battling for control of the border region for its first fatality.
Al Jazeera's Hashem Ahelbarra, reporting from Gaziantep on Turkey's border with Syria, said: "The Turkish army has intensified its military operation following the death of a Turkish soldier. Turkish sources say he was killed in an attack by [Kurdish] YPG fighters."
 
Turkey has long accused the YPG of being linked to the outlawed PKK in its own southeast. YPG is the military arm of the Syrian Kurdish PYD political party.
It has ordered the YPG, a well-trained force that has been the US-led coalition's most effective ground partner in the war against ISIL, to withdraw to the east bank of the Euphrates River, which crosses the Syria-Turkey border at Jarablus.
Turkey first sent tanks across the border on Wednesday as part of a stated two-pronged operation against ISIL, also known as ISIS, and Kurdish-led forces.
Our correspondent said the Turkish army has been "shelling and launching air strikes" in areas controlled by the YPG.
"These are areas that Turkey has asked the YPG to pull out of. The YPG insists those areas are part of their own terriritoty, and there's no way it will pull out. That will likely increase tension."