"It could be just one person – it does require a very large community to do this. However, a really coordinated attack could certainly bring a significantly more adverse outcome,” said cyber security expert at Teo, Omnitel, Giedrius Meškauskas.

Rimtautas Černiauskas of the National Cyber Security Centre of Lithuania said that Thursday’s attack was unprecedented in its size.

"The attack was in fact one of the biggest - problems were experienced by a significant proportion of Lithuanian websites," he said.

The attack targeted the server of the Information Society Development Committee protected by Infrastruktura (Infrastructure) state-run company.

"Information systems of a dozen of state institutions had connection problems and issues of accessibility of some websites," Sandra Gražytė, communications head for Infrastruktura said.