Brussels  - The EU's top foreign-policy official, Javier Solana, on Wednesday condemned in a statement the arrest of Zimbabwean opposition leader Morgan Tsvangirai and called for his release.

The arrest "will heighten further the fears of the Zimbabwean people and the international community about the conditions under which this poll, crucial for the future of Zimbabwe, will be held," the statement said.

Zimbabwe is set to hold a second round of presidential elections on June 27 after Tsvangirai out-polled incumbent Robert Mugabe, without receiving enough votes for final victory, in the first round on March 29.

Since that first round, sporadic violence between Mugabe's supporters and the opposition has left over 50 opposition activists dead.

Tsvangirai was detained while campaigning ahead of the second-round vote. (dpa)