Zimbabwe opposition leader Morgan Tsvangirai was detained by police on Wednesday in the approach to a run-off election on June 27, his Movement for Democratic Change party said.
"He has been taken into a charge office in Lupane," southwestern Zimbabwe, chief MDC spokesman Nelson Chamisa told AFP.
"It's the whole entourage of the president, including his security personnel and other senior party officials."
The MDC said in a statement that Tsvangirai had initially been stopped by police on a slip road while driving in the Lupane area and held for some two hours before being transferred to the police station.
Four MDC lawmakers have been arrested in the lead-up to the election at the end of the month when Tsvangirai is looking to topple President Robert Mugabe after 28 years at the helm of the southern African nation.
A leader of a breakaway MDC faction, Arthur Mutambara, was arrested on Sunday over an opinion piece, which was heavily critical of 84-year-old Mugabe's rule of the former British colony.
The party also says that 58 of its supporters have been killed by pro-Mugabe militias in recent weeks.
The MDC has faced severe restrictions in its campaigning efforts and Tsvangirai has been largely prevented from addressing party rallies.
During a visit to the southern city of Bulawayo on Tuesday, Tsvangirai said: "Mugabe is determined to turn the whole country into a war zone in order to subvert the will of the people and steal the June 27 election by any means possible.
"But we will not stop campaigning, the people will not stop supporting the MDC and together we will defeat this illegitimate and desperate regime."
Tsvangirai has been arrested on a number of occasions and twice been charged with treason.
The former union leader suffered head injuries in March last year after being assaulted by the security forces as he tried to stage an anti-government rally in the capital Harare.
Tsvangirai is only participating in the run-off election on June 27 under protest, insisting he won an outright majority in the first round in March.
Official results from the electoral commission gave Tsvangirai 47.9 per cent of the votes against Mugabe's 43.2 per cent.