Southern African leaders were set to meet with Zimbabwean President Robert Mugabe yesterday to discuss the deepening crisis in his country.
The emergency meeting of the Southern African Development Community (SADC), hosted by Tanzanian President Jakaya Kikwete, began on Wednesday as Zimbabwean police raided the headquarters of the main opposition party.
The 14-nation SADC is a regional bloc promoting development and democracy in the region.
Movement for Democratic Change (MDC) officials said that party leader Morgan Tsvangirai was among a group arrested by the security forces, a claim that police denied.
The raids on Tuesday and Wednesday during which 35 people were arrested -- part of an investigation into several recent firebombings which the police have blamed on the MDC -- have increased pressure on regional leaders.
While Western nations have sharply condemned Mugabe since opposition leaders were arrested and then assaulted ahead of a planned anti-government rally earlier this month, SADC countries have been more muted in their response, even though they have most to lose from the fallout.
Apart from the political unrest, an inflation rate of 1,730 percent and unemployment of 80 percent has led around 3 million Zimbabweans to emigrate and caused the virtual collapse of an important market for the region.
Tanzanian officials said SADC chiefs would try to convince Mugabe to meet the opposition MDC leaders in a bid to dissolve mounting acrimony that threatens the stability of the African nation.
US State Department spokesman Tom Casey said the US "is deeply concerned about the detention of Morgan Tsvangirai ... and other opposition officials today at the MDC's headquarters in Harare."
Southern African regional leaders may go further and tell Mugabe he must retire when his term expires next year, a former Mugabe ally told Britain's Guardian newspaper on Wednesday.
"They will remind Mugabe that he told them he would retire at the end of this term in 2008. They will tell him he must do that," said Jonathan Moyo, an information minister until he fell out with Mugabe in 2005.
Mugabe's ruling ZANU-PF party plans to announce today whether it will support extending his term until 2010.
The SADC summit was also expected to address the situation in the Democratic Republic of Congo after deadly clashes last week aimed between 200 and 500 lives.