An outspoken critic of Tanzanian President John Magufuli is missing after being snatched off the road by armed men in the country's far south, the main opposition party said Sunday.
Four men wielding guns abducted Mdude Nyagali, a high-profile dissident and opposition activist, as he left his workplace in Mbozi on Saturday evening, the Chadema party said in a statement.
Witnesses said the 32-year-old screamed for help before being pulled into one of two waiting vehicles which sped off, the statement added.
"So far, we don't know where Mdude is," Chadema said.
The incident had been reported to law enforcement, the party said. Police in Mbozi, a town in Songwe region near the Zambian border, could not be reached for comment.
Critics say Magufuli has unleashed a wave of oppression since his election in 2015, cracking down on opposition figures and curbing press freedom.
Two regime opponents, including a lawmaker, were handed five-month jail terms in February for defaming the president, who is nicknamed "The Bulldozer".
Nyagali, an acid-tongued critic of Magufuli, branded him a "hypocrite" in a Twitter post to his nearly 20,000 followers just hours before his disappearance.
He has faced sedition charges in the past.
The activist has been threatened online with the same fate as Tundu Lissu, an opposition lawmaker recovering in a Brussels hospital after being shot in September.
His Chadema party accused the government of trying to assassinate him.
Earlier this year more than a hundred Tanzanian civil society groups signed a rare joint statement condemning Magufuli's "unprecedented" crackdown on human and democratic rights.
In April, Reporters Without Borders said journalists were being "attacked with impunity" in Tanzania as the country slid 25 places on the World Press Freedom Index.