Madagascar's new government says half of the capital Antananarivo is without power after three electricity pylons were blown up on Friday.

A spokesman for the government of Marc Ravalomanana has blamed the attack on supporters of his presidential rival, Didier Ratsiraka.

The attack came as Mr Ratsiraka was in the Ethiopian capital, Addis Ababa, for a special summit on the crisis in his country.

State radio in Antananarivo said Mr Ravalomanana had left for the Addis gathering "out of respect for the OAU (Organisation of African Unity) and its unceasing efforts to find a solution".

Mr Ravalomanana was declared president by a Madagascan court last month after a disputed election in December, but the verdict has not been accepted by Mr Ratsiraka and his supporters.

Dogs of war

The stand-off between the two men has led to violence that has cost about 70 lives.

The leader of the new government says he will not attend the OAU summit

And a statement released this afternoon by the Ravalomanana government in Madagascar detailed yet another alleged operation to send mercenaries to destabilise the new government.

The communique details 36 mercenaries being sent from South Africa in three helicopters, according to certain sources.

Earlier, the new Madagascan Government said it would take legal action against Mr Ratsiraka and a group of alleged French mercenaries who it claims tried to enter the island in support of the former president.

The 12 men returned to France on Thursday, where they were questioned by French police.

But the French authorities said they were allowed to go free because they had committed no crime under French law.

OAU plan

Ratsiraka's camp denies links with the alleged mercenaries

Senegalese President Abdoulaye Wade is being joined at the summit by the leaders of Ethiopia, Mozambique, Tanzania and Zambia, as well as the deputy president of South Africa and foreign ministers from Togo, Namibia, Egypt, and Gabon.

Diplomats say the meeting will focus on an OAU plan put forward on 9 June.

It envisages a transitional government with an equal number of representatives from both the Ratsiraka and Ravalomanana camps to lead the country to early general elections.

Hopes for a peaceful solution appeared to fade on the eve of the Addis meeeting as Mr Ravalomanana withdrew an offer of amnesty for Mr Ratsiraka.

Crisis deepens

Mr Ravalomanana accused his rival of involvement in the alleged attempt to send the French mercenaries to Madagascar.

Mr Ratsiraka left Madagascar for France last week, and the Ravalomanana government says that if he returns, he will be prosecuted for trying to seek weapons and allies abroad.

The political crisis erupted six months ago, after presidential elections which the two men claimed to have won. Later, Mr Ravalomanana was formally declared the winner and appointed a government.

The BBC's Jonny Donovan in Antananarivo says that for many people in Madagascar, the latest breakdown in relations between the two camps means that Mr Ratsiraka's time is over.