The US deployed a team of special forces soldiers to Saudi Arabia‘s border with Yemen to help locate and destroy caches of ballistic missiles used by Houthi rebels to attack the Saudi capital, Riyadh, according to a New York Times report.

The newspaper, citing unnamed US officials and European diplomats, said on Thursday that a team of about a dozen Green Berets were sent to the Saudi-Yemen border in December last year.

They arrived weeks after a ballistic missile from Yemen came close to Riyadh, according to the report.

As well as working with American intelligence analysts to help locate Houthi missile sites inside Yemen, the US special forces are training Saudi troops to secure their border, the Times reported.

It claimed the American soldiers are also working with surveillance aircraft to track Houthi weapons and their launch sites.

The New York Times called the troop deployment a “continuing escalation of America’s secret wars”, adding that the move contradicted US military’s claim that its assistance to the Saudi Arabian-led coalition forces in Yemen is limited to “non-combat support”.

Senator Tim Kaine, a Democrat senator, believed the mission was a “purposeful blurring of lines between train and equip missions and combat”.

The Saudi-led coalition is battling Iran-backed Houthi rebels to restore the internationally recognised government of President Abd-Rabbu Mansour Hadi.

The war in Yemen has killed more than 10,000 people and displaced more than two million people.

Humanitarian crisis

The three-year civil war has contributed to a humanitarian catastrophe: about seven million people are on the brink of famine, while one million people are suspected to be infected with cholera.

President Donald Trump‘s administration has come under fire for its continued support for the Saudi-led war in Yemen.

The Senate in March debated a resolution seeking an end to US support for the Saudi-led coalition. The resolution did not pass.

The US state department has, meanwhile, approved a possible arms sale to Saudi Arabia worth more than $1bn.