A cargo aircraft transporting over 35 tonnes of arms from North Korea has been seized and its five-man crew detained after landing at Bangkok airport for refuelling, Thai officials have said.

The arms included missiles and grenades, Panitan Wattanayagorn, a spokesman for the Thai government, told Al Jazeera on Sunday.

"The incident is under investigation by the Thai police and tomorrow the five gentlemen will be processed through a court of law in Thailand," Wattanayagorn said.

"We believe that since the plane came from North Korea it violated UN resolutions and we will proceed accordingly."

Since carrying out a nuclear test in May, North Korea has been under UN sanctions aimed at cutting off its arms sales which are thought to net Pyonyang more than $1bn a year.

'Tangible proof'

The North's biggest arms sales come from ballistic missiles and its customers include Iran and other Middle Eastern states, according to US government officials.