The missiles North Korea launched toward the sea west of the Korean Peninsula on Wednesday had been its new strategic cruise missiles, according to its official media.

The state official Korean Central News Agency said Thursday that it had test-fired the new strategic cruise missile, whose name Pulhwasal-3-31 means fire arrow in Korean, for the first time the previous day.

North Korea’s Missile General Bureau said the first testing of the cruise missiles came as a “part of the process” of its “constant efforts to update weapons systems,” which were the “regular and obligatory activities” of the bureau and affiliated defense science agencies.

Other details such as how far the missile traveled were not included in Thursday’s announcement.

The last time North Korea launched a cruise missile was in September.

Pulhwasal-3-31 is speculated to be a variant or an update of the Hwasal-1 and Hwasal-2 cruise missiles, which were showcased in launches last year, and are thought to be capable of carrying nuclear warheads. North Korea said in an official media statement then that the cruise missiles were fired as a “tactical nuclear attack simulation drill.”

Cruise missiles tend be far slower than ballistic missiles, but they fly at low altitudes, making them tricky to detect.

Since the turn of the new year, North Korean military provocations have been intensifying.

For three days from Jan. 5, North Korea fired some artillery shells near the sea border with the South. Then it launched an intermediate-range ballistic missile on Jan. 14 and an underwater nuclear weapons systems on Jan. 19.

North Korean leader Kim Jong-un said on Jan. 15 that the concept of unification of the two Koreas and reconciliation with the South must be completely eliminated from the national history.

Seoul military and intelligence authorities anticipate an increase in North Korean belligerence this year ahead of the elections in South Korea and in the US.