XICHANG -- A pair of satellites launched from Southwest China have experienced abnormalities, the launch center said on Thursday.

The satellites, known as DRO-A and DRO-B, were launched at 8:51 pm (Beijing Time) on Wednesday from Xichang Satellite Launch Center in Sichuan province. A Yuanzheng-1S (Expedition-1S) upper-stage aircraft, attached to a Long March-2C carrier rocket, carried the two satellites.

The first and second stages of the rocket operated normally, while the upper stage encountered an abnormality during flight, causing the satellites to fail to accurately enter the preset orbit.

The relevant disposal work is currently underway, said the launch center.