Tanzanian police arrested the leader of the largest opposition party Saturday on charges stemming from his role in a political demonstration earlier this year.

Freeman Mbowe, a legislator and chairman of the opposition group, Chadema, remains in custody pending his arraignment Monday.

Mbowe and several others are accused of multiple charges including holding an illegal rally against election fraud in Arusha in January.

A judge issued an arrest warrant for Mbowe on Thursday, because he failed to make his initial court appearance last month.

The opposition party said in a statement Mbowe was taking part in parliamentary commission meetings at the time of his scheduled court appearance.