Six teenagers from the Burundi robotics team, who had come to Washington to compete in an international competition, were reported missing to D.C. police on Wednesday, according to police reports.

The team from the small east African country had competed in the inaugural international event of the FIRST Global Challenge robotics competition, which drew hundreds of young people from 157 nations to Constitution Hall in Northwest. The event opened Sunday with a parade of nations and closed Tuesday at around 6:30 p.m.

Police posted fliers of the missing teens on the department’s Twitter account, which stated the teens were last seen in the area 5 p.m. Tuesday, around the time the final robotics matches finished.

The missing teenagers range in age from 16 to 18 and include four males and two females, police said.

[YouTube: See the Burundi team during the competition in Washington]

“FIRST Global learned the adult mentor of Team Burundi is unable to find the group of six students of the team who participated in the 2017 FIRST Global Challenge,” according to a statement from an organization spokesman early Thursday.

“The proper reports have been submitted to the police who are investigating the case,” said spokesman Jose P. Escotto.

Escotto 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. Sestak then called a volunteer who helped Bindaba file a report with police.

Bindaba is listed in a previous press report as a team coach.

Officials from the Burundi Embassy in Washington could not immediately be reached late Wednesday.

A State Department spokesman referred all questions to local authorities.

According to six identical police reports, one filed for each missing teen, a mentor to the teens told the event volunteer the group went missing and that volunteer called police. The mentor later reported that “they traveled from Burundi Africa for the competition. They have one-year visas,” the reports state.

In each report, Bindaba told police that each teen “went missing after the competition and he does not know where he could have went.”

Police said they canvassed Constitution Hall with 2nd District officers but did not find the teens.

Each report said that police attempted to contact an uncle from one missing teen but received no response.

Escotto said he believed the Burundi team members had attended closing ceremonies which began at 5:30 p.m. Tuesday.

“Security of the students is of paramount importance to FIRST Global,” the organizer’s statement said. “FIRST Global ensures that all students get to their dormitories after the daily competition by providing safe transportation to the students staying at Trinity Washington University who are always to be under close supervision of their adult mentor and are advised not to leave the premises unaccompanied by the mentor.”

A spokesman for the university was not immediately available Thursday morning.

This week’s competition had already garnered global headlines after a group of teenage girls from Afghanistan’s team initially were denied visas to travel to the U.S. Organizers had previously hosted domestic competitions, but this was the first international event.

Police identified the missing teenagers on Twitter as:

Richard Irakoze, 18, a black male with a dark complexion who is 5-foot-11, 140 pounds; Kevin Sabumukiza, 17, a black male with a medium complexion who is 6-foot-4, 160 pounds; Nice Munezero, 17, a black female with a dark complexion who is 5-foot-7, 140 pounds; Aristide Irambona, 18, a black male with a dark complexion who is 5-foot-6, 130 pounds; Don Ingabire, 16, a black male with a medium complexion who is 5-foot-8, 130 pounds; Audrey Mwamikazi, 17, a black female with a dark complexion who is 5-foot-3, 130 pounds.

Officials did not have any description of the clothes the teens wore when last seen, only that they were last seen in the 1700 block of D Street NW.

Burundi is a small country in East Africa bordered by Tanzania, Rwanda and Lake Tanganyika.

The State Department issued a travel warning in late June, advising Americans of “political tensions, political and criminal violence, and the potential for civil unrest.”

That warning stated that rebel forces, ex-combatants and youth gangs from the Democratic Republic of Congo had reportedly attacked and kidnapped civilians, while armed groups have ambushed vehicles.

An earlier version of this story incorrectly identified the reason the teenagers on the Afghanistan team were initially denied visas to the U.S.