Washington, Jun 6 (IANS): Two US B-52 bombers flew within the vicinity of the contested Spratly Islands in the South China Sea, according to a statement from US Pacific Air Forces, which oversee air operations in the region, the media reported.

A US defence official said it called for the nuclear-capable bombers to fly about 32 km (20 miles) from the islands on Tuesday.

A spokesman for the Pentagon said the mission involved the Guam-based bombers conducting "a routine training mission", flying from Andersen Air Force Base in the US territory of Guam "to the Navy Support Facility" in the UK's Indian Ocean territory of Diego Garcia, CNN reported.

The bombers flew from Diego Garcia and conducted training in the vicinity of the South China Sea, returning back to Diego Garcia the same day, according to the statement from the US Pacific Air Forces.

The flyover came days after Secretary of Defence James Mattis accused China of "intimidation and coercion" in the Indo-Pacific, making clear that the US had no plans to leave the region. This triggered a furious Chinese response.

Beijing claims the Spratly Islands but those aren't recognised by the US or by China's neighbours -- Malaysia, Vietnam, the Philippines and Taiwan -- who say the islands are theirs.

China has used geographic features in the Spratlys to build man-made islands, some of which it has equipped with military facilities, including anti-ship and anti-aircraft missiles.