Riots broke out between Christians and Muslims in the northern city of Kano, and at least 30 people were killed, newspapers reported Thursday.

The violence started Tuesday in Kano’s central market after a Muslim of the Hausa ethnic group got into an argument with a Christian from the Ibo tribe.

Newspapers quoted witnesses as saying the dispute was over where stalls

could go at the market.

Fellow tribesmen joined the fray, and the fighting spilled into city streets. People battled with sticks, machetes and stones and rampaged through neighborhoods, burning shops and cars and attacking houses.