The FIRST Global Challenge robotics competition is making headlines again after six teens from the team representing Burundi disappeared. The mentor and chaperone for the team, Canesius Bindaba, informed FIRST organizers on Tuesday evening that he could not find the two girls and four boys, whose ages range from 16 to 18. They were last seen at 5 p.m. Tuesday, right before the competition’s closing ceremony. FIRST President Joe Sestak subsequently called Washington police, who began searching and tweeted out missing persons notices.

Metropolitan Police spokeswoman Aquita Brown said Thursday morning that two of the teens, 16-year-old Don Ingabire and 17-year-old Audrey Mwamikazi, have been sighted crossing the border into Canada. Police do not suspect foul play. Burundi is one of the poorest countries in the world and is struggling to recover from a 12-year civil war between ethnic factions. In its 2017 report, Freedom House labeled Burundi “not free” and warned that the country is experiencing “a shift toward authoritarian politics and ongoing repression of and violence against the opposition.”

This is FIRST’s inaugural Olympics-inspired international competition, which is meant to promote STEM among high school teens from more than 100 countries through games involving robots. The tournament received considerable media attention when a team of six girls from Afghanistan were twice denied the U.S. visas needed to attend. Upon learning of their predicament, President Trump reportedly intervened with the State Department to let the girls into the country. The team from Gambia’s applications for visas were also initially denied, but the department reversed its decision in the weeks leading up to the competition.