Tom Thabane said a coup was ''in the offing'' as demonstrators barred Prime Minister Pakalitha Mosisili, cabinet ministers and officials from their offices.

The protestors are angry at delays in releasing the results of an inquiry into allegations that the May poll was rigged to allow the ruling Lesotho Congress for Democracy to win 79 out of 80 seats.

Mr Thabane said: "I have seen coups in this country before so I know what I am talking about. A coup is in the offing.

"I went to my office this morning, but I had to drive back because I could have been killed.''

Protestors also locked the gates of parliament and warned anyone tampering with the lock they did so at their peril, the South African Press Association said.

They then went from door to door in government buildings and commercial offices, ordering civil servants and staff to leave.

Demonstrators also forced the Lesotho Bank to close its doors.

Government ''has lost control''

A Western diplomat in Maseru said the government had lost control of the situation.

"Things have gone so far that something must happen in the next 48 hours,'' he added.

"If coup means change of government by unconstitutional means then that is not here yet, but things are so serious that severe decisions have to be taken.''

The diplomat said the government did not have adequate control over the army to use it to regain control and could be forced to resign.

The election report was compiled by electoral experts from Botswana, South Africa and Zimbabwe after hundreds of protesters began a round-the-clock vigil at King Letsie's palace in Maseru on 4 August.

The team, led by South African Constitutional Court judge Pius Langa, completed its two-week probe at the beginning of September.

But release of the report has been repeatedly delayed.

Fraud report should be released this week

The latest protests follow an army mutiny last week when junior officers took senior officers prisoner.

Joe Modise: Emergency visit to thwart mutiny

The officers were released in an agreement brokered by South African Defence Minister Joe Modise.

During the weekend hundreds of anti-government protesters gathered outside the royal palace to call for the publication of the report.

So far five people have been killed at the palace in a number of shooting incidents.

In one case a policeman was shot dead when a gun battle erupted between soldiers guarding the palace and police who had opened fire on protesters.

Mr Thabane said he had informed the South African government of the situation in Lesotho and had been told that the report should be released this week.