Tanzanian police have detained a pastor after two worshippers drowned while being baptised in a river near Rombo in the north of the country.

The two victims were overwhelmed by the current of the River Ungwasi, a police spokesman has told the BBC.

It is not clear how the pastor and the other worshippers involved managed to survive, the BBC's Odeo Sirari says.

They are members of a local church, Shalom, which is part of the charismatic Christian movement.

Baptism in a river rather than in church is seen as a way of re-enacting the baptism of Jesus in the River Jordan.

The ceremony is a symbol of washing away sin and the start of a new life.