Nuclear-armed North Korea fired off "multiple" ballistic missiles Wednesday, the latest show of force in less than a week following the first release of images of one of its uranium enrichment facilities and the firing of multiple short-range missiles.

The Defense Ministry in Tokyo said the latest launches, which came between 6:53 a.m. and 7:23 a.m., saw the missiles splash down into waters outside Japan's exclusive economic zone.

The ministry, which usually details the trajectory of such launches, did not offer a map of the firings or any information on the distance the missiles had traveled.

The South Korean military also confirmed the firing of multiple short-range ballistic missiles, saying that all of the weapons had traveled about 400 kilometers (250 miles) but did report the exact number launched.

"Our military will maintain the ability and determination to respond overwhelmingly to any provocation," the South Korean Joint Chiefs of Staff said in a statement.

Tokyo, meanwhile, said it had strongly protested the firings, calling recent actions taken by the North a "threat to the peace and security of our country, the region and the international community," and adding that it was working closely with Seoul and Washington to analyze the launches.

Pyongyang offered a rare glimpse into one of its secretive uranium enrichment facilities, with state-run media reporting Friday that leader Kim Jong Un had visited a nuclear site, where he urged the introduction of more centrifuges for the weapons-grade material needed to “exponentially increase” the number of nuclear bombs in his arsenal.

A day before those revelations, the North fired off multiple short-range ballistic missiles — part of moves that some experts say are intended to keep Pyongyang on the busy agenda of the next U.S. president following the Nov. 5 election.