Cameroonian authorities have detained opposition chief Maurice Kamto and four of his supporters after he began to organize a national protest.

The protest was called for after Kamto’s party, the Movement for the Renaissance of Cameroon, claimed to have found irregularities in the recent election, according to the Associated Press.

The Cameroonian courts have charged the opposition leader with rebellion, insurrection, sedition and inciting violence. Several human rights organizations, such as Human Rights Watch, have called for the release Kamto and his supporters.

United Nations Spokesman Stephane Dujarric told The Associated Press, “We call on Cameroonian authorities to respect the freedoms of assembly, association and expression and stress the need for restraint by all political actors.”

According to Al-Jazeera, longstanding president Paul Biya received 71.3 percent of the vote in comparison to Kamto’s 14.2 percent in the election that took place in October 2018. Kamto has been garnering support after he lost the last election to the president of 36 years.

Few people turned out to vote in the Anglophone region of Cameroon. The region has been the site of clashes between Anglophone separatists and security forces.

More than 200,000 people have fled the region, according to Al-Jazeera.

In between the election and his arrest, Kamto had appealed to the courts of the the African Union to investigate possible voter fraud.

Jean-Claude Tsila, an administrator in the capital city of Yaounde, called on the protestors to “give up their plans,” according to The Associated Press. The government has prohibited several planned demonstrations in recent days.

The protest from Jan. 26-28, in which Kamto and his fellow party member were arrested, were met with tear gas, water cannons and live ammunition, however the Cameroonian government has denied any use of excessive force.

Cameroonian security forces have had a reputation of quelling dissent with heavy-handed action. In October 2017, security forces killed 20 people during demonstrations in the Anglophone region of Cameroon.

The outcry in Cameroon has spread to European nations with substantial populations from the African nation.

Protests in Germany and France broke into Cameroonian embassies, smashing portraits of Biya along the way, according to The Associated Press. Kamto denies organizing any foreign demonstrations.

“Kamto denounces this vandalism in diplomatic missions. He has never sent anyone to break anything,” stated Sylvain Souop, Kamto’s lawyer. Kamto stated that he “has confidence in the justice of Cameroon.”

Editor’s Note: Information from The Associated Press, Al-Jazeera and Reuters was used in this report.