Zimbabwe police raided a house used by executives of the prime minister's party, saying they were searching for weapons, the country's finance minister said Saturday.

Tendai Biti, secretary-general of Prime Minister Morgan Tsvangirai's Movement for Democratic Change, said about 50 armed police "ransacked" the house in a Harare suburb on Friday night.

He said a guard, Moffat Nyandure, and his wife were assaulted. Police told Nyandure to dig in the yard around the house in search of weapons, he said. Nyandure was made to dig with his bare hands for five hours.

A room occupied by a party official, who was at the house at the time of the raid, was searched and "valuable party documents" were taken, Biti said. Police "claimed" they had a search warrant, he said.

The house is used by MDC executives who visit from outside of the capital.

Police spokesman Wayne Bvudzijena had no immediate comment.

Biti said the raid was "provocation" by President Robert Mugabe's ZANU-PF party who wanted to see the unity government fail.

"They are behind this attack. Our decision of pulling out of the inclusive government infuriated ZANU-PF and this is the price we now pay for that decision," Biti said.

Tsvangirai withdrew temporarily from the coalition on Oct. 16. The unity government was formed in February after disputed elections last year.

While both parties say they remain committed to the coalition, many feel it is doomed to collapse.

Mugabe's long-time rival, Tsvangirai has condemned unilateral moves by the president to fill government posts, continuing human rights violations and attacks on activists by ZANU-PF militants and security forces.

But the catalyst for Tsvangirai's withdrawal was the case against Roy Bennett, a popular party member nominated by the prime minister as deputy agriculture minister.

Prosecutors unsuccessfully tried to send Bennett back to jail to await trial on charges linked to discredited allegations that he had plotted the violent overthrow of Mugabe.

"These acts of harassment are an attempt to intimidate us but we will not be intimidated and our disengagement will not be reversed until outstanding issues are resolved," Biti told reporters Saturday.

Mugabe, 84, has ruled Zimbabwe since independence from Britain in 1980.