Police in Tanzania have confirmed the arrest of several opposition figures, including the chairperson of the Chadema party, Freeman Mbowe, ahead of Monday's planned protests.

Police say the arrested politicians wanted to disrupt peace while protesting against the results of last week's elections.

The Chadema and ACT-Wazalendo parties have called for mass action from Monday to demand fresh elections.

Incumbent President John Magufuli was declared winner with 84% of the vote. His Chama Cha Mapenduzi (CCM) party also won an overwhelming majority in parliament.

The head of police in the commercial hub of Dar es Salaam, Lazaro Mambosasa, said Monday's planned protests would not be allowed.

He said some opposition figures were planning violent protests.

Others arrested include former Arusha Mjini MP Godbless Lema, former mayor Boniface Jacob.