F-7 rocket-propelled grenade launcher manufactured in North Korea, which suspected to have been used by the Hamas militant group, is seen in this photo, provided by the National Intelligence Service, Jan 8. Yonhap

South Korea's spy agency said Tuesday it cannot rule out the possibility of North Korea staging attacks involving drones and motorized paragliders amid suspicions over Pyongyang's ties with the Hamas militant group.

The National Intelligence Service (NIS) issued the warning in its annual report on global terrorism, as the North has been ramping up weapons tests and verbal threats amid allegations of its illicit arms transfers.

In January, the NIS confirmed suspicions that North Korean-made weapons are being used by the Hamas militant group in its war against Israel despite Pyongyang's repeated denial of such transactions.

"Suspicions are being raised over links between North Korea and Hamas in areas, including military training and exchange of tactics," the NIS said in the report.

"The probability of simultaneous infiltration and provocation using drones and motorized paragliders cannot be ruled out," it added.

In recent years, North Korea has repeatedly reaffirmed its stance against all forms of terrorism.

North Korea has a track record of staging terror attacks against South Korea in the past few decades, including the 1987 midair bombing of a South Korean airliner near Myanmar that killed all 115 people aboard.

The attack prompted the United States to put North Korea on its terrorism blacklist, but Washington removed Pyongyang from the list in 2008 to facilitate talks on ending North Korea's nuclear weapons programs.

In 2017, the U.S. redesignated North Korea as a state sponsor of terrorism. (Yonhap)