BEIRUT — While the Turkish military fired on targets in Syria on Friday, the governments of Turkey and Germany threw their weight behind calls for a Syrian ceasefire during a Muslim holiday next week, and the international envoy for the conflict arrived in Damascus to push for the plan.

The effort has taken on urgency after activists in recent days reported some of the heaviest air bombardments by President Bashar Assad’s military against rebel-held areas.

The renewal of cross-border fire, however, cast some doubt on the potential efficacy of a diplomatic push. According to a Reuters report, Friday’s shelling by the Turkish military was in retaliation for two Syrian shells that landed in Turkish territory earlier in the day.

Lakhdar Brahimi, the joint UN-Arab League envoy, was expected to meet Foreign Minister Walid al-Moallem on Saturday. Brahimi has called for a truce by both sides in the civil war during the four-day Eid al-Adha holiday that begins next Friday.

Turkish Foreign Minister Ahmet Davutoglu also said both sides should end hostilities “at least” through Eid al-Adha.

“It is especially important for the Syrian regime, which has launched bombs on its people with planes and helicopters, to halt these attacks immediately and without preconditions,” Davutoglu said.

He said the opposition must abide by the ceasefire as well.

German Foreign Minister Guido Westerwelle also called for a ceasefire, saying it would be “an important humanitarian glimmer of hope for people in Syria.”

Others who have joined the calls for peace include Assad’s allies in Iran. But both sides of the conflict have flouted previous ceasefires.

Despite the push for a ceasefire, activists reported more regime airstrikes Friday in the northern Idlib province. There were no immediate details on casualties.

Dozens were reported killed Wednesday and Thursday in airstrikes on opposition targets across Syria’s north.

On Thursday, Syrian warplanes hammered a strategic city captured by rebels, leaving behind scenes of carnage captured on amateur videos that showed a man holding up two child-sized legs not connected to a body and another carrying a dismembered arm.

The city of Maaret al-Numan, located strategically on a major north-south highway connecting Aleppo and Damascus, was captured by rebels last week and there has been heavy fighting around it ever since. Rebel brigades from the surrounding area have poured in to defend the town. Online videos have shown them firing mortars at regime troops, and they claimed to have shot down a government helicopter on Wednesday.

Since it was captured a week ago, the Idlib province city and surrounding areas have been the focus of one of the heaviest air bombardments since Assad’s military first unleashed its air force against rebels over the summer.

Activists say more than 33,000 people have been killed since the anti-Assad uprising started in March 2011.