Protesters gathered outside the U.N. headquarters in Beirut, Lebanon Sunday to demonstrate against President Bashar Assad. Credit: AP

According to Agence France-Presse, Syrian state media reported Tuesday that rebel forces had launched a rocket attack on a hospital in a government-held neighborhood of Aleppo, Syria’s second city, leaving at least three dead and 17 others wounded.

State news agency SANA reported that rockets hit Al-Dabbeet hospital in the Muhafaza district as part of a more widespread assault by rebel groups on areas controlled by President Bashar Assad’s regime.

In a statement, the Associated Press reports, the Syrian army said the attack had been launched by groups including the Nusra Front (Al-Qaeda’s Syrian branch), Ahrar al-Sham, and the Army of Islam. “Armed forces are currently working on repelling the attack and appropriately returning fire,” the statement said.

Meanwhile, the Syrian Observatory for Human Rights said, in rebel-held neighborhoods, three air strikes left an unconfirmed number of people dead.

More than 250 civilians have been killed in Aleppo since April 22, AFP reports. Just last week, 27 people were killed in an airstrike on a field hospital, supported by Médecins Sans Frontières, in a rebel-held neighborhood.