Spokesman Mark Weinberg said about 230 opposition supporters were sitting outside the compound's entrance seeking food and a safe place to stay.

"We are working with international organisations and local partners to look for safe places to take them," he told Reuters.

"Some of them look injured and I also saw a man in crutches. There are also some mothers with children."

President Robert Mugabe was re-elected at the weekend in a vote that was boycotted by the opposition and widely condemned as unfair by world leaders.

Zimbabwean opposition leader Morgan Tsvangirai on Wednesday rejected talks on a unity government, saying Mugabe must first stop violence and accept him as the rightful election winner.

Tsvangirai defeated Mugabe in the first round of the election on March 29 but withdrew from the runoff after he said pro-government militias killed 86 of his supporters.