Maseru - Lesotho's ruling party has clinched a landslide win in weekend elections, according to final results released on Wednesday, but the main opposition leader immediately challenged the outcome.

The Lesotho Congress for Democracy took 61 of the 80 parliamentary seats available, to only 17 for the opposition All Basotho Convention, which prior to the polls had been tipped to unseat Prime Minister Pakalitha Mosisili.

The LCD win should give 61-year-old Mosisili a third term in office in the tiny landlocked southern African kingdom.

Opposition leader Tom Thabane has been at the forefront of allegations about irregularities, such as registration problems and government officials bussing in voters to constituencies.

"My general impression is that the atmosphere was peaceful and I think we are all free to vote as we like, but I cannot add the word fair," Thabane told AFP.

He said he felt his party should have rightly won over 30 constituencies and would be taking some of his grievances to court.

Thabane said his supporters had been encouraged not to resort to violence, such as occurred over disputed election results in a 1998 poll when the capital Maseru was almost razed to the ground. The violence was only quelled when the South African and Botswanan armies intervened.

Only 79 of the 80 constituencies were announced due to the death of a candidate in one constituency.

Of the 40 seats that are decided on a proportional representation basis in the 120-member parliament, the LCD's alliance partner the National Independence Party won 21 and the ABC's alliance partner the Lesotho Worker Party took 10.

Development in Lesotho, one of the world's most impoverished countries, has also been handicapped by HIV and Aids, which affects 30 percent of the population.