Two young men’s bodies, likely from the Dominican Republic, were discovered within an Avianca (AVT p.CN) plane’s undercarriage while it was being serviced in the Colombian capital Bogota, according to reports released on Saturday by both the airline and the country’s attorney general’s office.

The bodies of two passengers who flew irregularly (stowaways) were found in the aircraft’s undercarriage upon landing at the El Dorado airport in Bogota, according to Avianca, which added that the discovery was made on Friday evening.

Avianca expressed sympathy for the families of the two people and added that though it inspects airplanes before every flight, the security of airports and their restricted areas is the responsibility of authorities.

“The technical investigation body of the attorney general’s office is carrying out urgent actions to identify the nationality and origin of the bodies aged between 15 and 20, Afro-descendent, which were found inside the airplane,” the attorney general’s office said in a statement.

Though no identification documents were found with the bodies, one was carrying currency from the Dominican Republic and a suitcase found with the men had paperwork from that country.

Those discoveries “infer that the men could have been on the plane since January 3,” when it was last in the Dominican Republic, the office said.

The plane was last given regular maintenance on Dec. 27, the attorney general’s office added, and has since traveled to Bogota, Guarulhos, near Sao Paulo, Brazil, and Santiago.

The bodies had been frozen and were partially thawed, the statement added, and one had burns.