Zambian police said Tuesday they had arrested two senior editors of the country's largest independent newspaper that was shut last week over alleged unpaid tax.
The daily Post newspaper has rejected the tax-collecting agency's claims that it owes millions of dollars and says the shutdown is an attempt to silence it ahead of highly-contested August elections.
Editor-in-chief Fred M'membe and deputy managing editor Joseph Mwenda are yet to be charged, police officials and newspaper staff told AFP.
They were arrested early Tuesday at the paper's offices in Lusaka.
"Fred M'membe and his newspaper are victims of an attempt by the state to silence critical media and those who speak truth to power," said Deprose Muchena, Amnesty International's director for southern Africa.
The rights group called for the two men -- and M'membe's wife who was also arrested -- to be released immediately.
The Post, which was established in 1991, has been critical of President Edgar Lungu, who defended the tax authority's move to shut down the paper.
Lungu's biggest challenger at elections is expected to be the United Party for National Development leader Hakainde Hichilema, who lost by a narrow margin in last year's election after the sudden death of Michael Sata.
The United States on Monday urged authorities to allow the Post to reopen.