Johannesburg, Sep 22 (DPA) In a surprise move prompted by an 'undisclosed security threat', the US government shut down all its facilities in South Africa Tuesday.

In the statement posted on its website, the US embassy in Pretoria said: 'Based on information recently received by the Regional Security Office, all US government facilities in South Africa will be closed on Tuesday, September 22, 2009.'

'Our current assumption is that all US government facilities will be open on Wednesday, September 23, 2009,' it added.

The announcement came as a surprise as the US government is not known to be under a specific threat in South Africa. The closure also affects the consulate general in Johannesburg.

US citizens living in South Africa had not received a message from the embassy informing them of a threat against US citizens.

The US embassy spokeswoman and South African foreign affairs spokeswoman could not be reached for comment. A spokesman for the South African Police Service (SAPS), which was briefing parliament Tuesday morning on the country's latest crime statistics, said the SAPS would issue a statement on the matter later.

A South African embassy employee in Pretoria said he was contacted by the embassy Monday around 6 p.m. and told 'everything was closing down due to a security threat' but given no further details.