Syrian mortar fire again struck a Turkish border village on Sunday, prompting artillery retaliation for the fourth day, AFP reported.
The Syrian mortar round hit Akcakale, the site of a similar strike on Wednesday, as Turkish Foreign Minister Ahmet Davutoglu said President Bashar al-Assad should be replaced by Vice President Faruq al-Shara.
The mortar round hit the grounds of a public building without causing casualties, Turkey's NTV news channel reported, adding that the building had been evacuated beforehand.
On Wednesday five civilians were killed in Akcakale in a mortar strike that provoked counter-fire, in the most serious incident since Syrian anti-aircraft fire brought down a Turkish warplane in June.
That incident caused a spike in tensions between the former allies and renewed fears of a broader conflict.
Turkey's parliament on Thursday gave the government the green light to use military force against Syria if necessary.
Akcakale's mayor was quoted by the semi-official Anatolia news agency as saying Sunday's mortar hit prompted an immediate response by Turkish artillery.
The UN Security Council on Thursday strongly condemned cross-border attacks by Syria and called for restraint between the neighbors.
Syria's commercial capital Aleppo, meanwhile, was rocked by the heaviest fighting of an almost three-month offensive against rebels, residents said.
An AFP correspondent said warplanes were overflying the rebel-held Bab al-Hadid and Shaar neighborhoods, where witnesses reported fierce fighting.
"This is the worst fighting we've seen here since the beginning of the Aleppo war," one Bab al-Hadid resident told AFP.
"It looks like the army is trying to push the rebels as far as it can from the Hanano barracks," the resident said, asking not to be identified.
As fighting raged in Aleppo, state television said government forces had pushed rebels out of two of their strongholds in Damascus province, Qudsaya and Hameh.
"Hameh and Qudsaya in Damascus province have been cleansed from the armed terrorists," the channel said, using the regime's blanket term for the rebels.
The Syrian Observatory for Human Rights said the government had taken control of Hameh and said the bodies of 21 men were found there.
(Arutz Sheva’s North American Desk is keeping you updated until the start of Shmini Atzeret and Simchat Torah in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)