All crew and workers have been accounted for after an oil rig being serviced at Palumbo Shipyards listed this afternoon.

The incident happened at 1.15pm.

Palumbo general manager Joseph Calleja said the rig listed when its crew were conducting a ballasting operation. The incident, he said, was not connected with the repair work being carried out by the shipyard.

Sources said that most workers were returning from their break when the incident happened. An eyewitness said the alarm went off as crew members rushed off the semi-submersible rig Noble Paul Romano, owned by Noble Drilling.

Another witness said there was a commotion as some employees could be heard shouting frantically.

Mr Calleja said the evacuation was carried out in a very efficient manner. No one was injured and no damage was sustained.

Palumbo said this afternoon the situation was under control.