The bodies of 54 people burned alive or hacked to death in ethnic clashes in the west African state of Guinea have been identified, a medic said on Wednesday, indicating that the death toll would continue to rise.

The violence broke out in the southern forest region early Monday when petrol station guards from the Guerze tribe in the town of Koule beat to death an ethnic Konianke youth they had accused of stealing.

A Guinean court Saturday meted life sentences to two ringleaders of a failed assassination attempt on President Alpha Conde that rocked the nation just seven months after its first-ever democratic presidential election.

Another six defendants were handed jail terms of between five and 15 years after 17 hours of deliberation overnight by the court in the capital Conakry.

At least six people were killed and dozens wounded on Saturday in the third straight day of riots pitting local residents against police in the Guinean capital Conakry.

Deadly violence has erupted in recent weeks in the west African nation, where opposition activists have accused President Alpha Conde of seeking to rig elections planned for June 30.

Amnesty International has urged Indonesia to probe the deaths of three Papua independence activists who were gunned down as they protested 50 years of Jakarta's control over the restive region.

Two men were killed last week at an anti-government rally in Sorong, western Papua, and a woman died in hospital on Tuesday from gunshot wounds sustained at the protest, according to Amnesty and witnesses.

At least two people were shot dead Friday in Conakry during fresh clashes between Guinean police and opposition protestors, a hospital source and an opposition official said.

"Three of our supporters were shot dead Friday in Conakry," senior opposition official Cellou Dalein Diallo told AFP. A medic at a hospital in Conakry was able to confirm two deaths.

U.N. Secretary-General Ban Ki-moon called on Friday for calm in the West African nation of Guinea, where political violence has left about 130 people wounded.

"The Secretary-General is concerned about reports of ongoing violent clashes in Guinea, which started in Conakry on Thursday," said a statement released by a U.N. spokesman.

A plane carrying a military delegation from Guinea to attend an annual armed forces day in Liberia crashed Monday in the Liberian town of Charlesville, Monrovia said.

"There has been a plane crash in Charlesville at about five miles (eight kilometers) from the Roberts International Airport," said Liberian Information Minister Lewis Brown.

The International Maritime Bureau said on Monday that a French-owned oil tanker that went missing off the Ivory Coast over the weekend is believed to have been hijacked by pirates.

The owners of the Luxembourg-flagged tanker with 17 crew on board lost communication with the ship on Sunday, Noel Choong, head of the bureau's Kuala Lumpur-based piracy reporting center told Agence France Presse.

Britain's Prince Charles and wife Camilla arrived in Papua New Guinea on Saturday where they were welcomed with a 21-gun salute and traditional songs and dances as a threatened protest failed to materialize.

Several thousand well-wishers had earlier gathered at Port Moresby's Jackson's International Airport to catch a glimpse of the royal couple who are on a tour from November 3-16 which includes Australia and New Zealand.

Abu Dhabi has signed a long-term contract with the world's biggest producer Guinea for the supply of bauxite ore for the United Arab Emirates aluminium industry, state media reported on Saturday.

The deal between Abu Dhabi investment fund Mubadala and Guinean firm Compagnie des Bauxites de Guinee will give the UAE "a strategic resource" for its aluminium industry and will help CBG to further increase its bauxite production, the official WAM news agency reported.