Mexico’s Navy Secretariat (SEMAR) continues with a search and rescue operation initiated after a helicopter operated by Heliservicios went down offshore the Ciudad del Carmen near Campeche Sound, en route to Petróleos Mexicanos (Pemex) offshore platforms.

The incident happened at 6:43 a.m. on June 21, approximately 11 nautical miles from Ciudad del Carmen when the helicopter went down , Mexico’s state-owned oil producer said in a press release.

The only two occupants were the pilot and his co-pilot, the Mexico City-based oil giant said.

SEMAR has already started an investigation into the root cause of the incident, Pemex said.