Syrian rebels in the central Homs province have taken over parts of an important arms depot, seizing a large quantity of weapons, a monitoring group said Wednesday. A Syrian security official inDamascus, speaking to AFP on condition of anonymity, denied rebels had advanced or seized weapons, but said the fighting was still under way.

The conflicting reports come just over two weeks after jihadists and other rebels launched a major offensive aimed at capturing one of Syria’s largest weapons depots, near Mahin in the Homs countryside.

The Syrian Observatory for Human Rights – a Britain-based group which relies on activists and other sources inside Syria – said more than 50 rebel fighters and 20 loyalists were killed in Tuesday’s battle. Fighters from Al-Nusra Front and the Islamic State of Iraq and the Levant (ISIL) – both linked to Al-Qaeda – and the Al-Khadraa and Baba Amr Commandos battalions “took over buildings of an army weapons depot near Mahin,” the Observatory said.