An emergency disaster alert is transmitted from the Seoul city government at 6:41 a.m. on Wednesday, calling on people to prepare to evacuate. (Yonhap)

Foreign residents of Seoul were startled and confused as they woke up to emergency sirens and an alert sent out by the city government early Wednesday morning, just after North Korea launched what it says was a space satellite.

At 6:41 a.m., the Seoul city government sent phone alerts and sounded sirens, warning people to prepare for evacuation without saying why -- or where they should evacuate to.

Many foreign residents did not immediately know what the alert and the blaring sirens were about, as the message was conveyed in Korean only.

Inger Winther Johannsen from Denmark, who lives in Itaewon, central Seoul, took screenshots of the message for Google's translation service, and got ready to evacuate.

“It was confusing. We were still in bed when we heard the sirens. At first we thought the sounds were part of construction work, but we soon realized that we need to evacuate,” Johannsen said.

“We looked outside and nothing was happening on the streets; no one was rushing out, and my husband’s Korean colleagues shared on a group chat what they were hearing in the news. We got the message that it was a false alarm just after we got dressed to evacuate.”

Johannsen said now she feels she should find out where to go in case of a future evacuation, should something like this happen again.

However, she said it was fair that the message was only in Korean as it is easy to get it translated, and most foreigners living and working in Korea would have a network where they can learn about what is happening.

Some people, though, were in much greater panic.

“I was so scared. Immediately messaged my parents saying I love them, went to my friend’s place, and tried to figure out what the hell was going on. My only solace was that no Koreans were panicking outside,” Instagram user tat_otaco wrote on The Korea Herald’s Instagram account.

Another user, this.momint, wrote: “I can’t believe that after all these years, emergency messages still aren’t available in multiple languages.”

“I almost had a heart attack, was so surprised because this alert is so loud and saying ‘evacuate Seoul.’ Where am I supposed to go? I was about to get out to the closest subway station with just my pajamas and a bag with my documents,” wrote _annek6, another Instagram user.

For mobile phones set in English, the messages showed up with a heading "Wartime alert" on Android, and "Presidential Alert" on iOS.

At 7:03 a.m., the Ministry of the Interior and Safety sent a follow-up mobile phone alert, saying the warning issued by the city of Seoul at 6:41 a.m. had been sent erroneously.

“They updated after 30 minutes of panic saying it was a mistake. Can’t believe it took them that long to correct something so serious,” wrote another Instagram user, _skyway_.

Those outside the Seoul area did not receive the alert message or hear the sirens, only finding out later about the mishap.

“I live in Pyeongtaek and am just now hearing about this. I guess my city isn’t in the danger zone? But even so, if this were to actually happen, what are we supposed to do?” asked Instagram user bnana_colli31.

“What (do) schools teach us to do in these emergency situations in case it does happen in the future?”