Bulgaria has made an official request to Libya for the repatriation of five Bulgarian medical workers who remain in Libya after their death sentences were commuted to life in prison.

The Bulgarian foreign ministry Thursday requested the transfer of the five Bulgarian nurses and a Palestinian doctor, who recently became a Bulgarian citizen. The request is based on a 1984 prisoner exchange agreement between Sofia and Tripoli. Bulgaria says the agreement would allow the medical workers to serve the rest of their sentences in Bulgaria.

The six have been convicted on charges of deliberately infecting more than 400 Libyan children with HIV. The medics have repeatedly claimed innocence. International health experts say unsanitary conditions in the hospital were the likely cause of the infections.

Libya's High Judicial Council on Tuesday commuted the original death sentences to life in prison after families of the children each received about $1 million in compensation.

The six have already spent about eight years in Libya's prisons.

Some information for this report was provided by AFP and AP.