North Korea says it has successfully carried out a hydrogen bomb test, which if confirmed, would be its fourth nuclear test and a significant advancement for its military ambitions.

A hydrogen bomb is more powerful than plutonium weapons, which is what North Korea used in its three previous underground nuclear tests.

“The first H-bomb test was successfully conducted at 10:00 (2030 ET) on Wednesday,” North Korea’s official KCNA news agency said.

This statement came after a 5.1 magnitude quake was detected close to its nuclear test site at Punggye-ri, indicating that a test may have been conducted.

“If there’s no invasion on our sovereignty we will not use nuclear weapon” North Korea also stated adding that “This H-bomb test brings us to a higher level of nuclear power.”

According to North Korea’s news agency North Korean leader Kim Jong-un  authorized the hydrogen bomb test on January 3rd.

A senior U.S. administration told CNN it could take days to obtain the scientific data to determine whether this was a successful test.

The United States Geological Survey reported a 5.1 magnitude quake that South Korea said was 49 km (30 miles) from the Punggye-ri site where the North has conducted nuclear tests in the past.