It was still too early to determine what caused Wednesday’s fire incident in the tunnel between Kappara and Magħtab, Enemalta said.

A spokesman said an internal inquiry set up on the same day of the incident was looking into the technical aspects.

“The inquiry started on Wednesday night but this is not something that can be concluded immediately because the board will be analysing technical matters to determine what caused one set of cables in the tunnel to catch fire,” he said.

The tunnel carries cables between the Magħtab station – where the Sicily interconnector lands – and the Kappara distribution centre.

Households in central Malta ended up without electricity supply for almost three hours. The interconnector had to be disconnected as a precaution while Civil Protection Department personnel and Enemalta technicians battled the blaze inside the tunnel.

Enemalta said a number of high voltage cables, including one of the 132 kV cables linking the Magħtab Interconnector to the national electricity grid, were damaged by the fire some 600 metres down the tunnel.

By Wednesday evening the interconnector was switched on again and synchronised with the Sicilian grid. The spokesman yesterday confirmed the interconnector was again being used to import electricity after alternative cables in the tunnel were deployed.

“Repair works continued throughout the night and are still ongoing, but it is still too early to determine what the cause was,” he said.

Wednesday’s incident rekindled memories of a much bigger incident in August 2014 when a faulty underground cable caused the road surface at the Marsa industrial estate to crack. This kick-started a chain of events that led to a nationwide power outage. The cable that fed into Marsa South Distribution Centre had caused the distribution centre to catch fire, leaving some families in the Qormi and Luqa areas without electricity for 18 hours.