A this morning reports that the Chinese navy has seized a unmanned submarine operated by the U.S. Navy from international waters in the . The United States has issued a formal statement demanding that China give us our robo-sub back.

The incident happened yesterday northwest of , a former American naval base in the Philippines, just as the , an oceanographic survey ship, was about to collect the underwater research robot.

, the vessel was taken by a Chinese ship that was following the Bowditch:

“They stole it,” a U.S. defense official said. The U.S. established bridge-to-bridge communications with the Chinese but they responded by saying that they were returning to normal operations and then left the area.

The issue is being addressed through diplomatic channels, the official said.

CNBC also reports that the drone was part of an unclassified program involved in collecting oceanographic data, including ocean temperatures, water salinity and clarity, and other data. The data can have use for both scientific and military uses, especially in the field of sonar use.

A report from , citing a Pentagon spokesperson, confirms the original account of what happened from the unnamed defense officials, and adds that it was definitely not a communications issue:

China seized the submarine midday Thursday after pulling alongside the USNS Bowditch, a U.S. oceanographic survey ship, as it was stopped in international waters of the South China Sea, said Capt. Jeff Davis, a Pentagon spokesman. The ship was near the Philippines about 50 nautical miles northwest of Subic Bay when the submarine was seized, Davis said.

The Bowditch was stopped in the water, retrieving two unmanned submarines when a Chinese Dalang III class ship “came alongside of it, put a small boat in the water, went out and seized one of these [unmanned vessels] itself,” Davis said.

“There were multiple attempts made over bridge-to-bridge radio to demand it back,” Davis said. The Chinese ship “acknowledged the communications on bridge-to-bridge radio. It wasn’t a radio problem. But ignored the request for it to be returned and took it.”

More as we have it.