An emergency text message alerting residents in Gyeonggi Province about balloons presumed to be coming from North Korea late on Tuesday caused public alarm and confusion, with controversy over the use of the English phrase "air raid preliminary warning."

According to Gyeonggi Province on Wednesday, it sent out the message about the detection of “unidentified objects” — balloons carrying what is presumed to be North Korean propaganda leaflets — to residents in 13 cities and counties in the province at around 11:32 p.m. Tuesday.

The message advised the residents to refrain from outdoor activities and to report to the military if they discovered any such objects. It also added the phrase "air raid preliminary warning" in English.

The Army's Capital Corps had requested for the province to send out the message to people in  the 13 regions within the balloons' assumed direction of travel. A provincial official said the English reference to an "air raid" was automatically attached in accordance with the rules of the national disaster management system.

The official said the term "air raid" was included as the initially unidentified objects presumed to be from North Korea fell under the category of aircraft. Other warning categories include ballistic missiles and reconnaissance satellites.