Syrian rebels captured a strategically important village from government forces in fierce fighting south of Aleppo that killed 73 people, the Syrian Observatory for Human Rights said Friday. The city of Aleppo has witnessed days of deadly bombardments as part of the worst fighting in the 5-year-old conflict that has killed more than 270,000 people and displaced millions.

The monitor group reported that insurgents, including the al Qaeda-linked Nusra Front, launched an attack Thursday on government forces at the village of Khan Touman, located near the Damascus-Aleppo highway.

"At least 43 Al-Nusra and allied fighters, including a local commander, and 30 on the side of the regime and allied militia were killed in the battle," said the British-based Observatory, which relies on a network of sources in Syria.

Over the past few weeks, some 300 people have died around Aleppo in clashes, which came amid a nationwide cessation of hostilities being in place since February. On Wednesday, the United States and Russia persuaded the Syrian government and rebels to extend the truce to cover the Syrian city of Aleppo. The surge in fighting in Aleppo has led to the collapse of a two-month ceasefire, which was brokered by the U.S. and Russia. Moscow has said the airstrikes on Aleppo target terrorist groups.

Meanwhile, a senior United Nations official told BBC Friday that an airstrike on a Syrian refugee camp that reportedly killed at least 28 people "could be war crime."

"The suspicion will fall initially on the Syrian government and we will want to make sure that they, or whoever it is, are fully held to account for this absolutely abominable act," Stephen O'Brien, the U.N. humanitarian affairs chief, reportedly said about the attack on the Kamouna camp in the northern Idlib province. "Be in no doubt that all these terrible acts, wherever they happen and whoever perpetrates them, will not be forgotten and the people who perpetrate them will be held to account."

Clashes between government forces and jihadist groups continued Thursday, with fighting reported near Khan Touman, south of Aleppo, BBC reported.

The monitoring site also said that the Islamic State group militants captured the Shaer gas field in the east of the country, killing 30 troops.