Updated 5.30 p.m.

Enemalta said this afternoon that it is investigating the cause of the second nation-wide power outage which shut down both power stations at 4.30 p.m. - just when engineers were completing the restoration of power after the first shutdown in the morning.

The corporation said it wanted to assure the families of its employees that no one had been injured and the damage was "of a technical nature."

The first shutdown took place at 10.30 a.m - coincidentally as Parliament was discussing the Enemalta budget. As the hours passed, many shops and businesses closed down, with workers being sent home by their employers.

A number of people were trapped in lifts, and Civil Protection Department employees were called to nine sites.

The power supply started being restored at about 11.30 a.m. but the power went off again at about 4 p.m. There were several localities, including Birkirkara, San Gwann and Gozo, where the supply had not yet been restored.

Enemalta had said earlier it was still investigating the cause of this morning's outage.

Meanwhile, the power cuts have also caused taps to run dry in several localities, such as Sliema and St Julians, which are supplied directly from reverse osmosis plants.