Washington, D.C., police say six teenagers from Burundi who competed in an international robotics competition were reported missing on Wednesday.

Two of the teens — 16-year-old Don Ingabire and 17-year-old Audrey Mwamikazi — were last seen leaving the U.S. and heading into Canada, the Metropolitan Police Department tells The Two-Way blog, adding that there is "no indication of foul play."

The six-person team participated in the first international high school robotics competition, called the First Global Challenge, earlier this week.

They were reportedly last seen on Tuesday, the final day of the competition.

The Metropolitan Police Department says it has no further information as of early Thursday afternoon about the whereabouts of Richard Irakoze, 18, Kevin Sabumukiza, 17, Nice Munezero, 17, and Aristide Irambona, 18, and adds that the case is under investigation.

The six teens — four males and two females — are shown smiling and posing with Burundi's flag on their team page on the competition's website. It says the teens were chosen from schools around the capital, Bujumbura, and are accompanied by a mentor.

According to The Washington Post, a spokesperson for the competition said "FIRST Global president Joe Sestak, a former Navy admiral and congressman, called police after receiving word from the team's mentor, Canesius Bindaba, that the teens had gone missing."

The Metropolitan Police provided NPR with six nearly identical police reports, which all state that Bindaba accompanied the teen to the robotics competition at Washington's DAR Constitution Hall. They each had one-year visas to the U.S. The mentor stated that each teen "went missing and he does not know where [they] could have went."

Authorities also says they canvassed the location where the event was held.

Burundi, which is in central Africa, has faced intense political unrest since 2015. "Hundreds of people have been killed, and many others tortured or forcibly disappeared," according to Human Rights Watch. "The country's once vibrant independent media and nongovernmental organizations have been decimated, and more than 400,000 people have fled the country."

The robotics competition previously attracted international headlines when Afghanistan's team of six teen girls were denied visas twice. As NPR's Laurel Wamsley reported, President Trump "intervened to find a way to permit the girls entry."

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