Blantyre, Malawi - A prominent Malawian activist on Tuesday handed himself over to the police, two days after authorities issued an arrest warrant against him following a call for anti-government protests later this month.

Police had been looking for Timothy Mtambo, leader of the Human Rights Defenders Coalition (HRDC), since Sunday, when fellow activists Gift Trapence and MacDonald Sembereka were also arrested.

More:

The HDRC has been behind many of the protests that rocked Malawi following last year's disputed presidential election, demanding the resignation of senior members of the electoral commission for allegedly mismanaging the polls in which incumbent President Peter Mutharika was declared the winner.

Last month, Malawi's constitutional court annulled the results of the May 2019 vote, citing widespread irregularities, and ordered a new election to be held within 150 days.

Parliament has since approved bills to hold a new election on May 19 but Mutharika, who has appealed the ruling overturning his election victory, has yet to sign them.

The detained activists had called on supporters to march to the president's official residence on March 25 if Mutharika refused to act by then.

Addressing his supporters during a weekend rally, Mutharika had warned the activists to stop organising demonstrations. "Be warned; your time is up, the party is over, get up and smell the coffee," he said.

Trapence and Sembereka were arrested hours later, and police launched a hunt for Mtambo, who surrendered on Tuesday as thousands took to the streets of the capital, Lilongwe, in a show of support for the activist.

"The nation should be informed that section124 of the penal code prohibits any person to incite or solicit another to break any law," read a statement from the office of the inspector general. "By inciting people to seal the State Residences on 25th March 2020, the three committed an offense under section 124 of the penal code."

In a statement on Monday, Amnesty International condemned the "deeply troubling" arrests.

"Many human rights defenders have been subjected to threats, including by President Arthur Mutharika and senior leaders of his party," said Deprose Muchena, Amnesty's director for East and Southern Africa.

"Malawi authorities must immediately and unconditionally release the detained activists. The authorities must stop threatening, harassing and intimidating human rights defenders and allow them to freely exercise their rights."

Charles Kajoloweka, a leader of the Youth and Society group and member of the HRDC, described the arrests "unlawful and orchestrated by partisan politics".

"We condemn it in the strongest terms possible and would like to call for their unconditional release," Kajoloweka told Al Jazeera.

"We would not allow the president and his corrupt regime to create a police state. We believe the arrest is an attempt by current leadership to muzzle a critical voice that has emerged in the country."

The government has rejected the allegations.

"There is nothing political about the arrest of the activists, but they have broken the law," said Mark Botomani, the minister of information and government spokesperson.

"No one is above the law [and] whether they call themselves Human Rights Defenders Coalition, they are not above the law, and there is nothing political about it."