The Office for Government Policy Coordination, the interior ministry and the Seoul metropolitan government will discuss improvements, the report said, citing a senior government official.

The warning system will be updated to provide information such as “who, when, where, what, how and why” so as to allow a calm response from the public, a presidential official was quoted as saying.

The text message sent to Seoul residents on Wednesday morning was widely criticised for being unhelpful, as it told people to prepare to evacuate without specifying where they should go and what the danger was.

In another alert soon after, the safety ministry said the previous one had been an error.

Seoul mayor Oh Se-hoon apologised for confusion over the city’s alerts but defended the decision to send one as a precaution, citing public safety.