Zimbabwe police raid Tsvangirai's office, arrest five

Zimbabwe's Prime Minister and President of the Movement for Democratic change (MDC) Morgan Tsvangirai (L) and his wife Elizabeth speak to the media after casting their votes in a referendum at a polling station in Harare March 16, 2013.

HARARE (Reuters) - Zimbabwe police arrested five people in a raid on the office of Prime Minister Morgan Tsvangirai on Sunday, a move that could spark concern about a return to political intimidation ahead of an election expected later this year.

Zimbabweans voted on Saturday in a referendum expected to endorse a new constitution to trim presidential powers and pave the way for an election to decide whether Robert Mugabe extends his three-decade rule.

As both the 89-year-old Mugabe and his rival Tsvangirai have endorsed the new constitution, it was not immediately clear why police had raided Tsvangirai's communications office.

"They arrested the principal director of research and development and three others. They also arrested their lawyer," said an official from Tsvangirai's office.

The official confirmed the lawyer arrested was Beatrice Mtetwa, a top human rights attorney who has previously represented Tsvangirai and has accused police of using heavy-handed tactics against Mugabe's opponents.

Police spokeswoman Charity Charamba could not confirm the raid but said she would address reporters later.

Tsvangirai and Mugabe have been in a power sharing agreement following a violent and disputed vote in 2008. While marked by low turnout, Saturday's vote was notably free from violence.

Results from the polls were still being verified at provincial centers. Officials have up to five days to announce the outcome.

(Reporting by MacDonald Dzirutwe; Editing by David Dolan and Sophie Hares)