Ethiopian prime minister Meles Zenawi yesterday said that leaders of the main opposition party would be charged with treason, accusing them of seeking to overthrow his government.

The leadership of the Coalition for Unity and Democracy (CUD) was detained last week during clashes bet-ween security forces and protesters that killed more than 40.

But in an interview with the Financial Times and the BBC, Mr Meles arguedthat the CUD leaders were not political prisoners.

"What we have detained is people who have tried to overthrow the duly constituted government and that in my view is treason under the laws of the country," he said.

"The agenda of the [CUD] leadership was not kept a secret from anyone; they have made many public statements saying they were going to have what they called a rose revolution here in Ethiopia. In other words, what they said is street action to change government."

Probably "thousands" of people were rounded up by the government, he said, adding that many had already been released.

The CUD, which claims the opposition was cheated of victory in May elections, has insisted it has only advocated peaceful protests, such as a boycott of government products called this week.

Mr Meles did acknowledge the protests were also fuelled by "anger" among the hundreds of thousands of unemployed youths in the capital. He also admitted the election results, which saw opposition groups increase their seats in parliament from about a dozen to more than 170, were a "huge" protest vote against his administration.

However, he defended the use of force by soldiers and police, saying some rioters were armed with machetes and grenades.

"I deeply regret loss of life on both sides," he said. "But given the circumstances where we have violent mobs, organised mobs of unemployed youths, destroying over 100 city buses, burning offices and so on perhaps one can understand inevitably there might have been some losses of life."

Dozens of people were also killed during similar protests in June.

"Parties have to be willing to compromise, but on the basis of the rule of law," Mr Meles said. "These people will have to learn that there is a limit beyond which expression of dissent bec-omes crime."

The violence erupted at a time of growing concern about the stalled peace process that ended Ethiopia's border war with Eritrea, and fears the conflict could be reignited.

Mr Meles said Eritrea might seek to take advantage of Ethiopia's domestic turmoil, but said his government would "not respond to any provocations from Eritrea short of total invasion of our country".