from the BBC
Eyewitnesses say MDC adviser Gandhi Mudzingwa was forced by nine gunmen into a car which then drove to the city centre on Monday afternoon.
It would bring to 18 the number of MDC activists and rights campaigners who have vanished in the past six weeks....
The MDC says it believes there is a systematic plot to decimate its structures, as well as civil rights groups involved in cataloguing violence and human rights abuses in Zimbabwe.
Zimbabwean women demonstrate on the streets of Harare on 9 December 2008
There are claims civil rights groups are being targeted in Zimbabwe
The BBC's Peter Biles in Johannesburg says there is also growing concern about the fate of Zimbabwe Peace Project director Jestina Mukoko, missing since she was kidnapped from her home last Wednesday.
An urgent court application is being filed, demanding police produce her if she is in custody.