A Libyan official is denying reports that up to 20 Somali prisoners have been killed during an attempted jailbreak in the city of Banghazi.

Libya's ambassador to Somalia told reporters in Mogadishu Tuesday that there was no prison escape that he is aware of, and that no Somali prisoners have been killed.

On Monday, VOA's Somali service interviewed a prisoner, Abdullahi Abdi Siad, who said five inmates were killed when guards opened fire during the escape attempt.

The prisoner added that guards put the death toll at 20.  That is the number reported Tuesday by two Somali news outlets.

Britain has pressured Libya to improve conditions in its prisons, which were once notorious for overcrowding, poor sanitation, and poor health care.

The British Foreign Office says on its Web site that conditions have improved in recent years, though overcrowding remains a problem.