Sierra Leone doubled its death toll from the highly contagious Ebola virus on Monday, as international aid organisations struggled to contain the deadly epidemic gripping west Africa.

"There are now 109 suspected cases of which 42 are confirmed," said a statement from the health ministry, adding that six more people had been killed by the tropical pathogen since a death toll of six was announced a week ago. 

A woman in Sierra Leone has died from the Ebola virus, a health ministry official announced on Wednesday, the second person in the west African country to succumb to the hemorrhagic fever.

"One of the seven Ebola patients, a woman admitted at the Isolation Center in the Government Hospital in Kenema, died on Tuesday," Dr Brima Kargbo, the chief medical officer, told Agence France Presse in a telephone interview.

Sierra Leone on Monday confirmed its first death from Ebola, with several more suspected to have succumbed to the deadly virus that swept across neighboring Guinea earlier this year.

"I can categorically confirm that the Ebola sickness has materialized," said health ministry official Amara Jambai.

United Nations chief Ban Ki-moon arrived in Sierra Leone Tuesday to oversee the closure of the organisation's peace mission, with the nation in recovery after a brutal civil war.

The secretary-general is due to attend a ceremony on Wednesday to formally shut down the U.N. Integrated Peacebuilding Office (UNIPSIL) which marks the end of 15 years of peace operations in the country.

Attackers killed a Rwandan peacekeeper in an ambush on a U.N. convoy in conflict-stricken Darfur on Sunday, the United Nations said.

At least 12 U.N.-African Union peacekeepers have been killed in the troubled Sudanese region in the past five months.

Greece said Monday it would hold as unsafe a Sierra Leone-flagged cargo ship that was seized last week laden with arms and ammunition possibly bound for war-ravaged Syria.

"The ship does not meet safety standards and for this reason it will be held," Merchant Marine Minister Miltiades Varvitsiotis said, in statements reported by the state-run Athens News Agency (ANA).

When the guns fall silent in Syria and the killing eventually stops, a key part of helping a traumatized people rebuild and heal will be bringing to justice those behind years of shocking brutality.

Even though there is no end in sight yet to the grinding war in which some 110,000 people have died, a group of international judges and experts is already working to give the victims a voice through a special court.

Liberia granted 300 Sierra Leonean refugees citizenship on Thursday at a ceremony to mark World Refugee Day.

Around 100,000 people fled Sierra Leone to neighboring Liberia in 1991 when rebels from the Revolutionary United Front attempted to overthrow the government of Joseph Momoh, starting an 11-year civil war that left 50,000 dead.

Julius Maada Bio, beaten into second place in Sierra Leone's presidential poll according to official results, denounced the election as riddled with fraud in a statement to AFP Saturday.

Incumbent Ernest Koroma was declared the victor by national electoral officials and sworn-in for a second term in office on Friday after sweeping 58 percent of votes in the election held a week ago.

Sierra Leone's President Ernest Koroma swept to a second term Friday, winning 58 percent of votes in a poll that observers praised for its peacefulness and which focused on the nation's post-war recovery.

The 59-year-old incumbent triumphed over his main rival Julius Maada Bio of the Sierra Leone People's Party (SLPP) who trailed with 37.4 percent of votes.