Trouble started when the protesters broke into a barrier mounted by the police while they were marching to the Unity Fountain, Abuja to demand the release of their leader, Ibrahim Zakzaky.
Reports say the police, on seeing the protesters break in to the barrier, began firing teargas at them.
Another report has it that the police also shot live bullets at the protesters.
No casualty has been reported yet so far.
It said, in retaliation, the protesters responded by throwing stones at the police personnel.