Syrian warplanes carried out airstrikes on rebels trying to storm a police academy outside Aleppo on Wednesday, Feb 27, while jihadi fighters battled government troops along a key supply road leading to the southeastern part of the city, activists said, according to The Associated Press.

The police academy has recently emerged as a new front in the fight for Aleppo, which is considered a major prize in the conflict. Activists say the government has turned the facility into a military base, using it to shell opposition areas in the countryside as well as rebel-held neighborhoods inside the city.

The Britain-based Syrian Observatory for Human Rights said clashes raged Wednesday around the complex, which is located in the suburb of Khan al-Asal.

“The rebels are still trying to storm the school, but they can’t because the regime is carrying out airstrikes and bombarding rebel forces,” said Observatory director Rami Abdul-Rahman.

He said at least six rebels were killed Wednesday in the fighting, bringing the three-day death toll to 37 opposition fighters and more than 50 regime troops.