The bodies of nine Japanese killed during last week's hostage crisis at a natural gas processing plant in Algeria were flown back to Tokyo on Friday along with seven survivors.

The clash at the Ain Amenas facility between the Islamist militant captors and the Algerian military claimed the lives of 10 Japanese and six non-Japanese employees of Yokohama-based engineering firm JGC Corp.

"I've had to report to you very lamentable results. I'm feeling truly heartbreaking grief," JGC President Koichi Kawana told reporters at the company's head office in Yokohama shortly after he returned from the resource-rich North African country aboard the same plane as the survivors and victims.