South Korea’s Navy is continuing its efforts to detect the first stage of the rocket launched by the North on Sunday by mobilizing a remotely operated vehicle, officials said Wednesday.

On Sunday, Pyongyang launched a long-range rocket, sending what it claims to be a satellite into orbit, but South Korea and the U.S. denounced it as a long-range missile test that squarely challenges relevant United Nations resolutions.

Upon the launch on the west coast, the rocket flew southward, dropping its first stage into the Yellow Sea off the Korean Peninsula at 9:32 a.m. The first stage exploded midair and fell in some 270 pieces.

Four minutes later, the rocket disappeared from the military‘s surveillance radar southwest of South Korea’s Jeju Island.

“We are continuing the search for debris of the rocket‘s first stage in waters southwest of Jeju Island,” said a military official.

Since Sunday, the Navy has been searching for debris, but failed to detect anything that might be debris of the first stage.

According to the military, the missile is believed to have a range of up to 13,000 kilometers, which could reach the mainland U.S. The range of the Unha 3 rocket, which the North launched in December 2012, was presumed to be around 10,000 km.

The North’s rocket launch came weeks after it conducted a fourth nuclear test on Jan. 6, prompting the UNSC to work on a new resolution for tougher sanctions against the North. (Yonhap)