Ethiopia's largest opposition group has accused the ruling party of using what it calls "illegal means" to cling to power.  The denunciation comes after the party of Ethiopian Prime Minister Meles Zenawi announced it had won a clear mandate to form the next government in national elections Sunday.

A spokesman for the four-party opposition Coalition for Unity and Democracy, Birhanu Nega, called the ruling Ethiopian People's Revolutionary Democratic Front's claim of a mandate as being premature, noting that the vote counting process from Sunday's parliamentary elections has not yet ended.

Late Monday, officials from the ruling EPRDF said that they had won the elections with 300 seats, but conceded that they had lost most seats in the capital, Addis Ababa, to the opposition.  

It is not known what percentage of the votes have been counted.  But the Coalition for Unity and Democracy says preliminary results show it won 92 seats in the 547-seat parliament and another opposition group, the United Ethiopian Democratic Front, gained as many as 15 seats.

Prior to the elections, opposition members of parliament numbered fewer than 20.

Earlier Tuesday, the head election observer for the European Union, Ana Gomes, reprimanded the government for making a victory announcement before officials of Ethiopia's National Elections Board could confirm any result, either for the ruling party or the opposition. 

"The observation mission thinks that these announcements are not proper and will continue to follow the counting and tabulation closely," said Ms. Gomes.

Ms. Gomes says despite claims of intimidation and irregularities witnessed at some of the 1000 polling stations EU observers visited on Sunday, they have been impressed overall with the electoral process.       

"The fact should be highlighted that the elections were generally held in an orderly, peaceful manner.  By comparison to previous elections, these elections were characterized by greater political inclusiveness," she added.

Former President Jimmy Carter, who led a U.S. delegation of 50 observers from the Carter Center, was even more positive in his assessment of Ethiopia's third national elections in 14 years and its first to be observed by international monitors.

"I would say 'superb.'  We have not had any results from anywhere in the nation that showed any provable interference with the people's right to express their preference," said Mr. Carter.

The United States has called for both sides to respect the election's outcome.

Turnout was high for Sunday's elections, seen as a crucial test of Ethiopia's commitment to embracing democracy for the first time in the country's history.

An estimated 85 percent of Ethiopia's 25 million registered voters went to the polls.  Official results are due on June 8.