WASHINGTON (REUTERS) - US law enforcement authorities are seeking six teenagers from Burundi who went missing after an academic robotics competition in Washington, DC.

The competition which drew international attention when President Donald Trump intervened to allow an all-girl squad from Afghanistan to enter the country.

Police say two of them were spotted entering Canada, declining to say what US state they crossed from.

The six teens were last seen Tuesday (July 18) afternoon.

They were staying in the dorms at Trinity University and took their clothes with them, but left their hotel room key cards in a chaperone's bag.

Police say they do not believe foul play was involved.

An investigation is underway to find the teens from Burundi, a country plagued by civil war.

The Royal Canadian Mounted Police said that anyone who crossed the border illegally would be returned to border services.