KIEV, December 8. /TASS/. Security measures have been increased at Ukraine's Chernobyl nuclear power plant after an anonymous phone call claimed a bomb threat at one of the station’s blocs, a deputy director general of the NPP said on Monday.

The phone call was received on December 5, and no suspicious items or persons have been discovered at the station following a thorough check, Yevgeny Katunin said in a statement.

Since then, the site has been on high alert and the security regime and patrolling of the territory have been increased. The effort involves Ukraine’s Interior Ministry and Security Service.

In April 1986, Ukraine witnessed the world's worst nuclear disaster when an explosion at the Chernobyl nuclear power plant released radiation, which spread over the western part of the Soviet Union and Europe.