The recent jamming of satellite navigation signals, which affected hundreds of commercial flights and ships in South Korea's border area, may have been carried out by an affiliate of the North's Reconnaissance General Bureau (RGB), a professor said at a conference on Thursday.

"North Korea can pull off various cyber attacks including electronic and psychological warfare, denial-of-service attacks and hacking into a network," Lee Dong-hoon, a professor at Korea University, said at a conference hosted by the Defense Security Command.

"The global positioning system (GPS) disruptions were likely carried out by the cyber warfare unit, an affiliate of the North's RGB," he added.

Since 2010, Pyongyang has launched a series of cyber attacks that disrupted Seoul's navigation signals. It has denied responsibility for the most recent GPS jamming attacks carried out between April 28 and May 13.

South Korean intelligence officials believe that North Korea runs a 3,000-strong cyber warfare unit under the direct control of the RGB, its top intelligence agency. The unit is in charge of distributing viruses and hacking into computer networks.