Super Typhoon Soudelor is barrelling towards Taiwan, Japan and China after leaving a trail of destruction in the Northern Marianas islands.

The cyclone has developed into the world's most powerful storm of the year with wind gusts up to 354kph that have ripped down telegraph poles and flipped over cars.

A state of emergency has been declared on the islands - where some 400 residents are sheltering in emergency accommodation after the storm tore roofs off homes and caused power cuts.

"I've seen multiple primary power poles down; I've seen cars flipped over the road; I've seen lots of torn roofs," John Hirsh, from the American Red Cross in Saipan, told Pacific Daily News.

Waves up to 30ft high hit the island of Saipan according to the National Weather Service, and 10 patients were being treated for cuts and bruises at the island's Commonwealth health centre.

According to Cora Ada, a representative at the centre, the injuries were probably caused by falling debris but were not critical.

Saipan resident Jacquelyn Belk told Pacific Daily News: "The wind busted out my bedroom window and flooded the room. I was terrified that my shutters would break my sliding doors."

"I saw power lines down everywhere and trees blocking roads. Driving around was like a maze just trying to weave around fallen trees."

Soudelor is forecast to surge west-northwest over the western Pacific Ocean during the next few days where it is expected to weaken before hitting Taiwan at the weekend.