North Korea appears to be making final-stage preparations for a military parade involving a large number of troops on a plaza at Mirim Airfield in Pyongyang, April 19, in this satellite image. AFP-Yonhap

North Korea appears to be making final-stage preparations for a military parade involving a large number of troops ahead of another key anniversary next week, according to satellite imagery reported by U.S. news outlets Wednesday.

More than 12,000 troops were seen gathering on a plaza at Mirim Airfield in Pyongyang earlier this week, Radio Free Asia (RFA) said. It cited commercial satellite imagery provided by Planet Labs.

The area is known as the secretive North's traditional parade training venue with a replica of Kim Il Sung Square, where such an event highlighted by goose-stepping soldiers and a show of major weapon systems is actually staged. The satellite imagery was taken Sunday, a week before the North celebrates the 90th founding anniversary of the North Korean People's Revolutionary Army (KPRA).

What is noteworthy is a large crowd spotted at Kim Il-sung Square, which indicates that the North's parade preparatory work is in the final stages.

Many people were seen with makeshift tents set up April 17 and 18, RFA said.

The Voice of America also carried a report based on satellite photos taken April 17 and 18 that showed a large crowd of people making formations with red flowers at the square.

The imagery showed a parking space of the parade training ground of the airport packed with vehicles, it added.

South Korea's military and intelligence authorities are paying attention to the odds of a massive parade around next Monday. They do not rule out the possibility of a nighttime event.

If held, the North could use it as a chance to again show off its strategic weapons, such as intercontinental ballistic missiles and submarine-launched ballistic missiles.

An informed source in Seoul expected the North to mobilize more than 20,000 troops for a parade this time, with tracked vehicles such as armored cars and transporter erector launchers already on the move.

On the weekend, the North test-fired what it claims to be a new tactical guided weapon.

Last Friday, Pyongyang celebrated the 110th anniversary of the birth of its late founder Kim Il-sung with fireworks and a mass dance performance but without staging a military parade. (Yonhap)