SEOUL - An emergency evacuation alert sent in error across Seoul over a North Korean rocket launch triggered widespread panic on Wednesday, crashing internet services and raising fears the government could not be trusted to handle a real crisis.
The alert, sent at 6:41am local time to all mobile phones in Seoul, said: "Citizens, please prepare to evacuate and allow children and the elderly to evacuate first."
The message did not specify why residents should evacuate or explain where they should go -- Seoul has long had a network of underground bomb shelters, but they have not been used in emergencies in living memory.
Naver, South Korea's largest internet portal, told AFP its network went down for around five minutes due to the excess traffic sparked by the alert.
After around 20 minutes of confusion, the government retracted the alert.
"We inform you that the alarm sent at 0641 was incorrectly issued," a second alert said.
The retraction prompted anger and frustration, including calls on social media for Seoul Mayor Oh Se-hoon to resign.
The alert was triggered after North Korea launched a rocket carrying a military spy satellite, which crashed into the sea.
But it flew over waters west of the peninsula and not the Seoul metro area, the South Korean military later confirmed.
"It was a space launch out over the ocean," tweeted Jeffrey Lewis, a non-proliferation expert at the Middlebury Institute of International Studies.
"It's like if Japan issued shelter-in-place warnings every time South Korea did a space launch."
But the authorities in Seoul defended the alert.
As North Korea had launched the rocket to the south, the city government "judged that immediate action was necessary", Mayor Oh said in a press conference.
"This emergency text may have been an overreaction but... there can be no compromise on safety."
Oh said the city would further refine its warning system to avoid public confusion and issue appropriate guidance.
On Twitter, many South Koreans expressed frustration over the poor messaging from the government.
"They didn't tell us why we needed to evacuate, nor did they tell us where we needed to go," wrote user @duckdo_1226.
"I think I'll just end up being killed if a real war breaks out."