SEOUL (AFP) — North Korea fired two short-range ballistic missiles on Friday, Seoul's military said Saturday, the latest in a flurry of sanctions-busting weapons tests.

The launch comes at the end of a year that has seen Pyongyang conduct an unprecedented number of tests, including last month's launch of its most advanced intercontinental ballistic missile yet, with a range capable of hitting the US mainland.

Earlier this week, Pyongyang also claimed to have developed new capabilities to take images from space.

"Our military spotted two short-range ballistic missiles launched by North Korea into the East Sea from the Sunan area of Pyongyang at around 16:32 (0732 GMT) today," South Korea's Joint Chiefs of Staff said, referring to the body of water also known as the Sea of Japan.

The two missiles flew around 250 kilometers (155 miles) and 350 kilometers (217 miles) respectively, before splashing down into the East Sea, it added.

Tokyo also confirmed Pyongyang's launch, with its top government spokesperson Hirokazu Matsuno calling the North's latest provocations "absolutely unacceptable."

The United States and South Korea have warned for months that Pyongyang is preparing to conduct its seventh nuclear test.

The two countries held a joint air drill on Tuesday, and deployed a US B-52H strategic bomber to the Korean peninsula, according to the South Korean Joint Chiefs of Staff.

The long-range heavy bomber was part of an exercise that included the United States and South Korea's most advanced jets — including the F-22 and the F-35 stealth fighters.

Experts say North Korea is particularly sensitive about US-South Korean joint air drills as its air force is one of the weakest links in its military, lacking high-tech jets and trained pilots.