Anti-riot police fired tear gas and water cannons to disperse hundreds of peaceful demonstrators and arrested over a dozen people in Yaounde on Tuesday.
Demonstrations began after police barred four opposition parties from holding a press conference to counter calls by the ruling party for another constitutional amendment.
The parties include the CPP, UPC Fidele, UNIVERS and CRM. The parties have planned more demonstrations next month in what is expected to be another showdown with authorities.
Edith Kahbang Walla of the CPP said the police trampled political rights.
“We ask the public to be alert we will have a massive demonstration from the week of the 4th to the 9th of April to stop the modification of the constitution,” she said.
“The police have stopped us today from having a mere press conference. The police as you see, they have blocked us, they will not allow us to talk to journalists, they will not allow us to do our job as political leaders of this country, they have stepped on the rights of citizens”.
Martin Motase, the Divisional Officer for Yaoundé VI ordered the disruption and arrests. He said the press conference organisers did not have authorization.
The rally came in the wake of speculations that the regime might modify the constitution to favor an early presidential election, probably at the end of the year as called for by supporters of the ruling party, including ministers and lawmakers. The next presidential election is due in 2018.
Cameroon last modified the constitution in 2008, stripping term limits and allowing President Paul Biya in power since 1982 to seek another term in 2011.
Biya is likely to accept calls from his supporters to run again in an early election.