A Syrian government airstrike on a bitterly contested neighborhood in the northern city of Aleppo on Saturday killed at least 15 people, including nine children, activists said.

The Britain-based Syrian Observatory for Human Rights said the air raid hit Aleppo’s Sheikh Maqsoud neighborhood, parts of which rebels seized last weekend after days of heavy fighting with government troops.

That gain had been the latest opposition advance in an urban war zone that expanded last summer when rebel fighters took control of several neighborhoods. Aleppo is Syria’s largest city and a key front in the civil war raging between President Bashar al-Assad and those trying to overthrow him.

The Observatory said the death toll from Saturday’s air raid, near a checkpoint of anti-government Kurdish militiamen known as the Popular Committees, is expected to rise, as many others were seriously wounded.

Both sides are eager to control the strategic district, which is mostly inhabited by minority Kurds. The neighborhood is located on a hill on the northern edge of Aleppo and overlooks much of the city, giving those who control it the ability to pound districts held by the opposing side with mortar rounds and artillery.

The rebels control large swaths of northern Syria and captured their first provincial capital, the city of Raqqah, last month. They have also been making gains in recent weeks in the south, seizing military bases and towns in the strategically important region between Damascus and the border with Jordan, about 100 miles from the capital.

Meanwhile in Damascus, mortar rounds hit the residential district of Kafar Souseh on the city’s western outskirts, killing one person and wounding at least 13, the state-run SANA news agency said.

The Observatory said mortar rounds also struck the Damascus suburb of Jaramana. There were no immediate reports of casualties. It was not immediately clear who fired the shells.

The regime has largely kept the rebels at bay so far in Damascus, although opposition fighters control several suburbs of the capital and look increasingly capable of threatening the heart of the city and Assad’s power.

The Observatory also reported clashes between government troops and rebels Saturday in the town of Otaybah, east of Damascus.

Also Saturday, the newly elected prime minister of the Western-backed opposition umbrella group, Ghassan Hitto, started reviewing candidates for a planned rebel interim government that will consist of 11 ministries and will be based inside Syria, according to a statement by the Syrian National Coalition.

The candidates for ministerial and deputy positions must be Syrian citizens older than 35 years of age, the statement said, adding that high-ranking government officials will not be considered.

The Western-backed opposition alliance has been marred by severe divisions in its ranks since its formation late last year in Qatar, and its leaders are mostly seen as disconnected from the myriad rebel forces fighting in Syria.

— Associated Press