The six medics were accused of infecting 426 children with HIV while they were working at Al-Fateh hospital in the Libyan seaside city of Benghazi, during the 1990s. Fifty three children have since died.

Bulgarian lawyer Georgy Gatev said from Tripoli that the defense will appeal the ruling.

Bulgaria said it categorically rejected the "absurd" death sentences and called on the Libyan authorities to intervene.

"The whole court case was compromised and covers up the real cause that sparked the AIDS epidemics in Benghazi," said a joint statement by Bulgarian President Georgy Parvanov and Prime Minister Sergey Stanishev.

Parvanov also called on the international community to reject the Libyan decision.

Meanwhile, in the Bulgarian capital Sofia, parents and supporters of the five nurses launched a protest in front of the Libyan embassy.

EU shocked by verdict

EU Justice Commissioner Franco Frattini also called for the verdict to be reviewed saying he was "shocked" by the decision.

"I strongly hope that the Libyan authorities will rethink this decision," Frattini said. It poses "an obstacle to cooperation with the EU," he added. Bulgaria is to join the European Union on January 1.

German Foreign Minister Frank-Walter Steinmeier said it was "terrible to imagine how much horror the six medics have had to endure."

"This sentence further extends their martyrdom," Steinmeier said.

French Foreign Minister Philippe Douste-Blazy joined the condemnations, saying he was "shocked" by the verdict. He appealed to Libyan judicial authorities for clemency for the six medics.

The six, who were first detained in 1999, had already been sentenced in May 2004 to face a firing squad but the supreme court then ordered a retrial following a December 2005 appeal.

Relatives of the victims carried portraits of dead or sick children outside the courthouse as security forces fired into the air to keep the crowds at bay.

"Why me?" were the words on one picture. "Will I live for long?" asked another.

Medical evidence supports innocence

Defence lawyers argued that the children had been infected with HIV --the virus that brings on Acquired Immune Deficiency Syndrome -- before the nurses began working at the hospital.

In November, the renowned British medical journal The Lancet -- in an editorial entitled "Free the Benghazi Six" -- blasted the retrial as a miscarriage of justice with "no legal foundation".

It cited independent scientific evidence that the infections were caused by bad hygiene at the Benghazi hospital, and reports from human rights watchdogs that confessions had been extracted under torture.

Trial political minefield

Western trial observers say the foreigners are being used as scapegoats to cover up the negligence of Libyan health authorities. Some analysts suspect Libya is likely to keep the six as bargaining chips until talks yield a financial payout from the international community to appease the children's families.

Libya has demanded 10 million euros ($13.11 million) in compensation for each infected child's family. Bulgaria and its allies have rejected this, saying a payout would admit guilt.