A fire at a warehouse in South Korea killed 38 construction workers and left another 10 injured according to reports.

The blaze at the unfinished four-storey warehouse site in Icheon on Wednesday, 80km (50 miles) southeast of Seoul, spread “extremely quickly” and rendered those inside “unable to evacuate”, South Korea’s Yonhap news agency reported citing fire officials.

Eight of the injured were in a serious condition, local officials said. Firefighters said the blaze started on the second underground level, Yonhap reported.

Suh Seung-hyun, chief of the Icheon fire station, told Yonhap that oil droplets may have ignited to start the blaze, but police and firefighters were investigating the exact cause of the accident.

Witnesses said they heard at least 10 explosions.

President Moon Jae-in ordered government officials to mobilise all available resources in the search and rescue effort, Blue House spokesman Kang Min-seok said.

Moon hosted an emergency meeting and ordered medical support for the injured, Yonhap said.

The president also voiced regret that another massive blaze had occurred in spite of new government safety measures following fatal fires in 2017 and 2018.

“It is regrettable that a similar accident reoccurred. It means we’ve not learned the lesson from previous accidents,” Moon was quoted as saying by Kang.

In December 2017, a fire at a sports centre in the central city of Jecheon killed 29 people and wounded 40 others. One month later, a hospital fire occurred in the southeastern city of Miryang, killing 45 people and injuring 147 others.