North Korea may fire an intercontinental ballistic missile (ICBM) on a standard trajectory toward the North Pacific following its sixth nuclear test conducted a day earlier, South Korea’s intelligence agency said on Monday.

The National Intelligence Service (NIS) told lawmakers in a closed session that Pyongyang may launch the missile around the anniversary of the regime’s foundation on Saturday or the establishment of the ruling Workers’ Party of Korea on October 10, reports Yonhap News Agency.

North Korea fired ballistic missiles, including two ICBMs in July at a loft angle to prevent them from crossing over other countries including Japan.

But Pyongyang launched a Hwasong-12 intermediate-range ballistic missile that flew over Japan last week.

“There is a possibility that the North would fire an ICBM on a standard trajectory,” the NIS said.

On Sunday, North Korea claimed that it had successful tested a hydrogen bomb that can be mounted on an ICBM.

The NIS said the latest detonation was conducted in a northern tunnel of its nuclear sites.

Since 2006, the North has conducted six nuclear tests, including two last year.

“As North Korea has completed the construction of the third tunnel and another one is under construction, it can carry out another nuclear test at any time,” the agency added.