WASHINGTON — The police were searching on Thursday for six African teenagers who were reported missing from an international robotics competition in Washington. Two of them were said to have been seen crossing into Canada, law enforcement officials said.

Police officials here confirmed that two members of the robotics team from Burundi, Don Ingabire, 16, and Audrey Mwamikazi, 17, were seen entering Canada, but their destination and current location remained unknown.

It was unclear where the remaining team members were. They were identified as Aristide Irambona, 18; Nice Munezero, 17; Kevin Sabumukiza, 17; and Richard Irakoze, 18.

The six teenagers were last seen in Washington on Tuesday night near the Daughters of the American Revolution Constitution Hall, where the robotics competition took place. The team’s mentor, Canesius Bindaba, reported their disappearance after he returned to the dormitories where they were staying, assuming the teenagers had taken a different shuttle bus after the closing ceremony.