Eight people were traveling aboard the aircraft, which was on a humanitarian mission, the Mexican Navy Secretariat said in a statement.

Two people survived the crash while five others died, according to the agency, increasing the death toll from two as previously reported.

One person on the flight remains missing, despite search efforts by the US Coast Guard, the secretariat added.

The accident occurred as the aircraft was approaching Galveston, Texas.

The specialized medical transport mission was coordinated with a Mexican foundation that cares for children with severe burns.

According to the flight tracking website Flight Radar, the plane took off from Merida in Mexico's Yucatan state at 18:46 GMT and was last recorded at 21:01 GMT over Galveston Bay, near Scholes International Airport.