Hundreds of residents in Tokyo scrambled for cover as the Japanese Capital conducted its first-ever missile evacuation drill, preparing its citizens for a scenario of an incoming North Korean missile, Reuters reported on Monday.

Pyongyang has test-fired several missiles over Japan in the last few months. In September 2017, North Korea had conducted its sixth and largest nuclear test, firing a missile that flew over Japan before landing in the Pacific Ocean.

“An advisory about a missile launch was just issued,” an announcement during the evacuation drill said. “Everyone, please stay calm and seek shelter in the basement. Those who are already indoors, please stay there.”

Some participants huddled into an amusement park basement or a subway station in the Capital city while others took shelter at a community centre during the drill. Employees at the Tokyo Dome amusement park, pretending to be visitors, left rides and calmly marched to a basement. Meanwhile, a volunteer went around shouting, “A missile was launched.”

A few minutes later, another message via loudspeaker was circulated: “The missile has passed. The missile likely flew over the Kanto [greater Tokyo] region towards the Pacific Ocean.”

More than 20 such drills have been conducted across Japan since 2017. However, this was the first missile evacuation drill in Tokyo, AP reported.

“A missile from North Korea would arrive in less than 10 minutes and the first alert would come about three minutes after launch, which gives us only around five minutes to find shelter,” said Hiroyuku Suenaga, a Japanese government official, according to Reuters.