Three officials from Zimbabwean Prime Minister Morgan Tsvangirai' MDC-T office were arrested Sunday morning, party spokesman Douglas Mwonzora told Xinhua.

He said no charges had been preferred against them, and that when their lawyer Beatrice Mtetwa went to the police to establish what was happening, she was also arrested.

Sources said the trio might have been arrested on allegations of masquerading as police officers.

Mwonzora added that the police had also searched Tsvangirai's offices in Belgravia, just outside the city center.

The arrest occurred just a day after the country held a referendum to decide on a new constitution draft. All major political parties urged their supporters to pass the draft. It is not yet clear whether the arrest is in any way related to the constitutional progress.