SOFIA, Bulgaria - Death sentences handed down in Libya for five Bulgarian nurses accused of deliberately infecting 400 children with HIV triggered outrage Wednesday in Bulgaria, where the rulings were described as "a political farce" and a "mockery of justice."

People protest behind a poster which reads 'The World watching You God also', during a protest in front of the Libyan embassy in the Bulgarian capital Sofia, Tuesday, Dec. 19, 2006. [AP]

A court in Tripoli on Tuesday convicted the nurses and a Palestinian doctor and sentenced them to death, despite scientific evidence the youngsters had the virus before the medical workers arrived in Libya.

"The Libyan 'court' humbly carried out the orders of one of the longest serving dictators in the world," wrote the independent Monitor daily, which also carried the headline: "Deadly Christmas present from (Libyan leader Moammar) Gadhafi."

Some columnists called for economic sanctions or even breaking off diplomatic relations with the north African country.

"The solution is in a sharp, quick and open attack ... as a fully fledged EU member, Bulgaria should demand a European economic and diplomatic blockade on Libya," said one of the most popular dailies. Bulgaria will join the EU on Jan. 1.

The largest trade union in Bulgaria urged citizens working in Libya to leave the country. "Their labor and human rights will find no protection there," the union said in a statement.

Doctors and nurses from hospitals across the country protested against the sentences, while civic groups organized demonstrations and appealed for the nurses' immediate release.

The six have been in jail since 1999 on charges that they intentionally spread the HIV virus to more than 400 children at a hospital in the city of Benghazi during a botched experiment to find a cure for AIDS. Fifty of the children died.

Bulgaria and European officials have blamed the infections on unhygienic practices at the hospital, and accuse Libya of making the accused scapegoats to cover up poor conditions.

Libyan investigators told the court that infections were limited to the part of the hospital where the Bulgarian nurses had worked.

"The whole trial was a giant political farce ... It was a mockery of justice, falsified and manipulated," said Velislava Dareva, a journalist who heads a nongovernment association campaigning for the nurses' release.

"These death sentences are the cover for Libyan authorities to hide their guilt and their responsibility for the humanitarian disaster in Libya, where more than 100,000 people now live with AIDS."

Some commentators and editors called on Bulgaria's allies - the EU and the US - to increase the pressure on Tripoli to free the health workers.

"Libya needs a tool for influence, but not just over Bulgaria ... it targets mainly the European community and the U.S.," the independent Dnevnik daily wrote in an editorial. "If Gadhafi wants something from the West, it's up to the West to give him an adequate answer.

US Secretary of State Condoleezza Rice said after Tuesday's ruling the United States was "very disappointed with the outcome" and urged the medical workers be freed and "allowed to go home at the earliest possible date."

The European Union said it was "shocked" by the verdict. Spokesman Johannes Laitenberger said the EU had not yet decided to take steps against Libya while the ruling is appealed - but he "did not rule anything out."