At least four university students were killed on Friday and two others injured in a rocket attack by Syrian rebel groups on a university dormitory in the northwestern province of Aleppo, as deadly clashes between Syrian government forces and rebels in the province entered their third day.

The UK-based Syrian Observatory for Human Rights (SOHR) said shelling in al-Hamdaniya, a neighborhood in the city of Aleppo, where the dorms are located, also caused significant material damages.

The observatory reported at around 6:15 pm local time (10:15 a.m. ET) that the rebel forces had entered five neighborhoods within the city of Aleppo, following violent clashes and two “suicide operations.” The neighborhoods, which include Hamadaniyeh and New Aleppo, are located on the western edge of the city. The advance marked the first time rebel forces entered the city proper since they were ousted in 2016 following the victory of government forces there.

On Wednesday, Hayat Tahrir al-Sham (HTS), the former Al-Qaeda affiliate that controls Idlib province, the last rebel stronghold in Syria, launched a surprise assault on the government-held region. It is one of the most serious escalations in the province since a ceasefire was reached between Russia and Turkey to end confrontations between their forces in the northwest in 2020.