SEOUL, South Korea >> Satellite photos show hundreds of people in formation at a training ground in North Korea’s capital in a possible sign the country is preparing for a military parade amid heightened animosities over its recent missile tests.

The 38 North website, which specializes in North Korea studies, said today the Feb. 5 imagery taken on the Mirim airfield in Pyongyang — where rehearsals for past military parades occurred — likely signals a forthcoming parade.

North Korea often marks important anniversaries with parades and other displays, and the website noted several upcoming occasions, such as next week’s 80th birthday of Kim Jong Il, the late father of current leader Kim Jong Un, and April’s 110th birthday of Kim Il Sung, the late grandfather of Kim Jong Un.

The three Kims, who have been ruling North Korea successively since its foundation in 1948, are the subject of a strong personality cult among its 25 million people. The birthdays of the two late Kims are the country’s most important holidays, and its powerful Politburo recently decided to celebrate their upcoming birth anniversaries “with splendor” and make them as “the great festivals of victory and glory to shine long in the annals of the country.”

North Korea hasn’t disclosed what events it would hold to mark the upcoming birth anniversaries. But on past birthdays and other key state anniversaries, North Korea often paraded goose-stepping soldiers and new weapons systems through a main Pyongyang plaza to bolster unity and intimidate its rivals.

Last month, North Korea carried out a spate of missile tests in what some experts called an attempt to boost its weapons arsenals and pressure the Biden administration to make concessions such as sanctions relief. It appears to be pausing the tests during the Winter Olympics in China, its most important ally and economic lifeline, but observers say North Korea could test bigger weapons after the Olympics.

In a call Thursday, the defense chiefs of the United States, South Korea and Japan emphasized that North Korea’s recent missile tests “are destabilizing to regional security” and they committed to continue efforts to achieve the denuclearization of the Korean Peninsula, the U.S. Department of Defense said in a release. It said the U.S. commitment to the defense of Japan and South Korea is “ironclad.”

During the call, South Korean Defense Minister Suh Wook described the North’s tests as “a direct and serious threat to us” and said Seoul would bolster its own military capability and military alliance with Washington, according to his ministry.

It’s not clear whether the latest purported parade preparation was related to Kim Jong Il’s birthday or Kim Il Sung’s.

The 38 North website said training at the Mirim airfield in recent years usually began one to several months ahead of the festivities. South Korea’s military said last month it had detected signs that North Korea was preparing for military parades.

Ahead of previous parades, the website said large numbers of trucks and other military vehicles were often parked in the fields around the practice area. It said such vehicles weren’t seen in the current image, indicating an upcoming event will consist largely of people or that vehicles have yet to arrive.