Zimbabwe's government has indefinitely suspended all work by aid groups and non-governmental organisations, accusing a number of breaching their terms of registration.
The suspension comes nearly a week after President Robert Mugabe's government banned some aid groups from distributing food, accusing them of campaigning for the opposition Movement for Democratic Change in general elections held last March.
Earlier today police detained US and British embassy staff at a roadblock after they visited alleged victims of political violence.
According to a US embassy spokesman the police held five US citizens, two Zimbabwean staff and four British citizens for several hours.
'Police put up a roadblock, stopped the vehicles, slashed the tires, reached in and grabbed telephones from my personnel,' US Ambassador James McGee said in an interview on CNN.
The embassy said the diplomats were released after several hours.
Meanwhile, police released Zimbabwean opposition leader Morgan Tsvangirai after holding him for more than eight hours.
Mr Tsvangirai was detained yesterday as he campaigned for a presidential election run-off, along with the vice president and chairman of his Movement for Democratic Change.
The MDC said Mr Tsvangirai's four-vehicle convoy was stopped at a roadblock manned by police and members of President Robert Mugabe's feared Central Intelligence Organisation.
He was held at a rural police station southwest of Harare.
Mr Tsvangirai, who has been arrested several times in the past, defeated Mr Mugabe in a 29 March presidential election but failed to win the absolute majority needed to avoid a second ballot.
The run-off is scheduled for 27 June.
In March last year, Mr Tsvangirai was detained and badly beaten in police custody after he tried to attend a banned anti-government rally in Harare.
