"It was not a painful incident, everything was reset in a few hours," Economy Minister Viktor Uspaskich said in parliament.

Saulius Kutas, head of Lithuania's nuclear safety body VATESI told AFP that the cause of the May 17 shutdown was still being investigated.

"But it did not pose nuclear safety problems," Kutas said.

During the incident, energy was provided by Kruonis power station and from neighbouring Latvia.

Under commitments made to the European Union during accession talks, Lithuania shut down one of the two Chernobyl-type reactors at Ignalina on December 31 last year.

It plans to close the facility completely in 2009.

The EU has promised to finance the closure of the Ignalina plant, estimated at between two and three billion euros (2.5-3.75 billion dollars) over 30 years.

However, the Lithuanian government is considering building a new nuclear plant, using Ignalina's infrastructure.