Cyprus's ex-defence minister, Costas Papacostas, was sentenced to five years in jail on Friday in connection with a munitions dump blast at a naval base that killed 13 people.

The ailing 73-year-old was not in court for the sentencing, as he was taken ill after his conviction last month and has been in hospital since then.

He had been found guilty of manslaughter and the lesser charge of causing death through a reckless and dangerous act.

The July 2011 blast took out the island's biggest power plant 150 metres (yards) away and caused three billion euros ($4 billion) in damage that forced roaming power cuts amid 40 degree centigrade (104 Farenheit) temperatures.

Fire chief Andreas Nicolaou, his suspended deputy Charalambos Charalambous and disaster response unit chief Andreas Loizides were also convicted of causing death through a reckless and dangerous act.

They were sentenced to two years on Thursday.

Former Foreign Minister Markos Kyprianou and ex-deputy National Guard Chief Savvas Argyrou were found not guilty in the case. Prosecutors have appealed the decision, which sparked angry protests from relatives of the victims.

It is said to be the first time in the island's legal history that so many senior officials have faced such serious charges.

The incident sparked weeks of angry street protests calling for then president Demetris Christofias to step down.

A public inquiry laid most of the blame for the blast on Christofias, whose immunity shielded him from prosecution and who refused to resign.

The munitions were seized in 2009 when Cyprus intercepted a Cypriot-flagged freighter bound from Iran for Syria. A UN sanctions committee said the cargo contravened a ban on Iranian arms shipments.

Stored at the base for almost three years under searing heat in summer, they exploded despite repeated warnings that they were unsafe and the government's rejection of offers from abroad to neutralise them.

Some 98 burning containers with 400 tonnes of gunpowder triggered an estimated 1.5 megaton blast that also damaged 730 homes and businesses.