Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

South Korea responded on Friday to a nuclear test conducted by its northern neighbor by blasting Korean pop music toward the isolated rogue nation, an official said.

"We are sending out K-pop and information about life in South Korea as well as about North Korea," a South Korean military official told NBC News. South Korea had warned the broadcasts would resume.

North Korea was internationally condemned after it conducted a suspected nuclear test that it claimed was a hydrogen bomb — a claim that if true would mean a significant advancement of its nuclear abilities.

But U.S. and other officials expressed deep skepticism about the claims. The seismic event recorded during Wednesday’s test, a magnitude of 5.1, is similar to those recorded during earlier nuclear tests conducted by North Korea, experts said.

The Morning Rundown Get a head start on the morning's top stories. This site is protected by recaptcha

Tensions between the countries over the suspected nuke test have put a dent in tourism, a South Korean business owner who lives in a city close to the border with the north said.

Related: Can North Korea Handle Blowback After Stoking World Crisis?

"My restaurant is only a few kilometers from the border to the North, and that was the marketing point,” Kim Eun Joo, a resident of the city of Paju, said in a phone interview.

"But I only have two tables for lunch today, as all tour reservations have been cancelled," Kim said.

The South Korean military official said the country is "continuously maintaining heightened military alertness" after the nuclear test.

South Korea has broadcast propaganda messages from loudspeakers towards North Korea in the past. The two nations have technically been at war since the 1950s.

The use of loudspeakers ratcheted up tensions between the two countries last year, before South Korea agreed to halt them.

British Foreign Secretary Philip Hammond urged South Korea to show restraint, saying the country "is simply rising to the bait," Reuters reported. Hammond's comments were made during a visit to Japan.

Kim, the restaurant owner, shrugged off the military alert sparked by the alleged nuclear test.

"To me these alerts have become a part of life, and I go about life as usual," Kim said.