A controversial Tanzanian Muslim cleric has been arrested for stoking religious hatred, police have said.
Sheikh Ponda Issa Ponda's arrest comes after Muslim protesters vandalised and torched five churches in the main city, Dar es Salaam, last week.
The violence followed rumours that a Christian boy urinated on a Koran.
More than 120 people had earlier been arrested over the attacks - one of the worst cases of religious conflict in mainland Tanzania.
The 14-year-old boy was also taken into police custody on Friday for his own safety.
Angry Muslims then marched to the police station to demand that he be handed over for "punishment".
When police refused, the group attacked churches in the city's Mbagala area.
Dar es Salaam police commander Suleiman Kova said Sheikh Ponda had been arrested for giving speeches that incited people to hate other religious groups and the government.
This influenced people to stage protests similar to those that led to last week's violence, he said.
"He's been conducting various activities, including that of organising demonstrations without following the right channels," Mr Kova added.
Sheikh Ponda is the head of the influential Council of Imams, which is involved in a long-running power struggle with a government-backed group of Muslim clerics known as Bakwata.
Mr Kova said Sheikh Ponda had also been arrested because his group was operating illegally.
"Through his institution, he's threatening the well-being of other Muslim leaders," Mr Kova added.