SEOUL — Sirens blared out over the South Korean capital at 2 p.m. Wednesday, but no one took much notice. In the center of Seoul, cars stopped — but only because police officers with fluorescent batons made them. Pedestrians outside City Hall went down into the subway, but only because metropolitan officials directed them down there.

The increasingly brazen threats coming from North Korea in recent weeks have caused jitters in Washington, but residents of Seoul — who live within artillery range of North Korea — have been pretty much carrying on as usual.

“I’ve read the stories in the papers about the threats, but this time doesn’t feel any different from the other times,” said Kim Young-ae, an office worker who was meeting some friends after lunch. She wasn’t going to bother with the drill — she had somewhere to be.

“I think this is how most South Koreans think,” she said.

The South Korean government simulated an air raid on Wednesday to encourage people to prepare for an attack from North Korea. When the sirens went off, people were supposed to stop what they were doing and take cover.

For the first time, planes were also supposed to fly over the city emitting colored smoke, meant to represent the enemy’s bombs. But the heavy rain and low cloud meant that even the planes couldn’t be seen, let alone any smoke.

The drills, which take place as South Korean and American forces conduct joint exercises to prepare for an attack by or on North Korea, have been taking place every year since 1972.

This year’s drills were little changed from previous years, despite the steadily increasing threat. After all, North Korea’s development of an inter-continental ballistic missile able to reach the United States changes nothing for South Koreans, who have been within range for decades.

Instead, the emphasis was on making sure their message got through.

“We are trying to send a message to the public that there are simple things they can do to save their lives, such as seeking shelter underground as soon as possible,” said Jung Han-yul, director of the civil defense division at the Interior Ministry.

Seoul, a city of some 10 million people, has more than 3,200 underground shelters, many of them in subway stations or parking garages, or even tunnels on the highway. But they were designed to withstand attacks with conventional artillery, not chemical or nuclear weapons.

People even a mile away from the detonation point could be saved if they were deep enough underground, Jung said.

An instruction sheet put out by the ministry tells people to move underground as soon as the sirens go off, plus some unlikely guidance for what to do in a nuclear attack.

People should lie down but facing the opposite way from where the nuclear bomb landed, and they should keep their mouth open while covering their eyes and ears. They should also make sure their stomach is not touching the ground — purportedly because if a nuclear bomb is dropped, it would shake the ground so much that it could damage the internal organs.

Some residents, while disinterested in the drills, still think that the preparations are not enough.

“North Korea will not attack Guam with a nuclear missile. North Korea will attack South Korea with chemical and conventional weapons, but South Korea is not ready for that kind of attack,” said Seok Hwan-soon, a journalist for a magazine covering tax issues.

The citizens’ hall, a common space under City Hall, was already full with its usual weekday crowd of pensioners after lunch Wednesday.

Civil defense officials tried to whip up some excitement among them for the drills, saying how they needed to practice responding to a chemical attack, but most continued to look at their phones.

“Please applaud if you understand this,” an official with a microphone called out. Then he turned to low-level bribery. “If you participate properly, I’ll give you the gas masks for free. You need to move fast — there’s a Washington Post reporter here.”

The “volunteers” who’d be cajoled up onto the stage were still struggling to figure out how to put on their masks when the siren blared again, marking the end of the drill.

Yoonjung Seo contributed to this report.