Chinese state media on Monday said it had successfully detonated a hydrogen bomb in the northwest Chinese city of Yan’an, a day after a United Nations arms embargo on the country was lifted.

The blast occurred near a military base that has been a popular tourist destination since the 1990s and was said to have been placed near a high-security area.

An image of the device showed it being fitted with a solid-fuel warhead, a type of explosives that is less likely to cause a chain reaction of fires or explosions.

“It was a very good test,” state-run Xinhua news agency quoted an unnamed military officer as saying, without giving details.

The Chinese military had previously said that its latest attempt was a test of a new warhead that is more accurate than the one that was tested last year.

It has not given details on how the hydrogen bomb was made or how long it took to make it, which is expected to be around a year.

China, a former colonial power that emerged in the 19th century as the world’s largest economy, is now developing its own nuclear weapons program, which it hopes will counter US influence in Asia.