SEOUL, South Korea — North Korea marked its government’s 69th anniversary not with another missile test, as many had feared, but with a gala party for the scientists involved in carrying out the country’s most powerful nuclear test yet last week, the state-run news media reported on Sunday.

The country’s leader, Kim Jong-un, celebrated the national holiday on Saturday by bringing his nuclear scientists and engineers to Pyongyang, the capital, and holding a banquet.

On their way from the country’s underground nuclear test site in northeast North Korea to Pyongyang, the technicians had been cheered by people who poured out to see them passing by, the country’s official Korean Central News Agency reported. And upon their arrival in the city, on Wednesday, they were met with a hero’s welcome, including a huge outdoor rally and firecrackers.

North Korea described the test, on Sept. 3, as the detonation of a hydrogen bomb that could be delivered on a missile. Mr. Kim’s government called it “a merciless sledgehammer blow to the U.S. imperialists.”