Emergency authorities in the Commonwealth of the Northern Marianas say the Anatahan volcano is now erupting every ten seconds.
The volcano is spewing rocks and ash emissions more than 16 hundred metres into the air.
The Emergency Management Office's, Juan Takai Camacho, says he flew over the eruption last Friday.
He says they have advised people to stay away from the uninhabited island, located north of Saipan.
"It's still an off limits zone and the emergency declaration is still in effect. No entry to that island, in a radius of 10 nautical miles around it."