"As we speak, there are yet (more) distributed denial-of-service attacks on our country taking place," Liudas Alisauskas, the head of National Cyber Security Centre, told reporters.

A distributed denial-of-service (DDoS) attack is designed to overwhelm the target with a flood of internet traffic, preventing the system from functioning normally.

The cyberattacks targeted the Vilnius municipality's websites, including tourism information site and a public transport app.

"These are basic services that are needed to be available to our guests," Alisauskas said.

The National Cyber Security Centre said it is currently reinforced with more staff and cooperates with intelligence agencies and police, as well as foreign partners.

The centre said it had also received a report on Sunday regarding two other cyber incidents, one of which involved the hacking of a regional radio station.

The station's broadcast was interrupted by disinformation targeting NATO and Ukraine.

Lithuanian telecommunications provider Telia also said on Monday it tracked down calls on Telegram channels to attack various Lithuanian state institutions and companies.

Lithuania gears up to host the NATO summit on Tuesday and Wednesday.