After taking part in an international robotics competition in Washington DC, six Burundi teenagers have been reported missing. Two of the students were seen leaving the US for Canada.

A police spokesperson said authorities "do not have any indication of foul play" as the investigation continues into what happened after the group attended the FIRST Global Challenge robotics competition with students from 157 nations.

Four of the teenagers seem to be in a safe place, but police are not reporting any details as yet, according to the Washington Post.

Police reports provided to Buzzfeed indicated that the four boys and two girls were last seen in the early evening of 18 July in northwest DC after which their adult mentor was unable to locate them. FIRST Global informed the police later that day.

Audrey Mwamikazi, 17, Nice Munezero, 17, Don Charu Ingabire, 16, Kevin Sabumukiza, 17, Richard Irakoze, 18, and Aristide Irambona, 18 reportedly have one-year US visas.

However, the Burundi Embassy in Washington said by email that it did not know about the robotics contest or if a Burundian team was attending.

The DC police have said that Ms Mwamikazi and Mr Ingabire are the two in Canada, but no details have been released about how they got there or why.

Canada's Border Services Agency said it could neither confirm nor deny that the pair entered Canada.

During the competition, the students were staying in a dormitory on the Trinity Washington University campus, but a Univeristy spokesperson said FIRST Global had full responsibility for the students.

The keys to the students' rooms were left in the mentor's bag and their clothes had been taken from the rooms, the organisation said.

This was the first international robotics competition FIRST Global has held.

Burundi, for which the US State Department has issued a travel warning, has been experiencing civil unrest after a failed coup in 2015.

There have also been reports of human rights abuses as well. According to the UN, over 300,000 people fled the country since 2014 due to violent gangs from Congo and disappearances and killings allegedly committed by Burundian security forces.