Palestinian Authority policemen clashed Sunday night with hundreds of protesters in the Al-Amari refugee camp at the southern entrance to Ramallah.
At least 23 protesters and 15 policemen were injured, three of them seriously, during the clashes, Palestinians said.
The confrontation erupted when PA policemen tried to prevent demonstrators from blocking the main entrance to the camp, eyewitnesses said.
The demonstration was held in solidarity with Palestinians held in Israeli prisons, they added.
Policemen and security officers used gas tears and live ammunition to disperse the protesters, according to the eyewitnesses.