Relatives of four Japanese volunteer workers in Jordan who died after a traffic accident Friday in the southern part of the country departed for Amman Sunday afternoon, the Japan International Cooperation Agency officials said.

The 11-member group, including the four men’s wives, was accompanied by two officials of JICA, which organized the volunteer program.

The group is scheduled to arrive in Amman via Frankfurt by Monday morning Jordan time, but details of their itinerary have yet to be finalized.

Killed in the accident were Tsuneo Kawatani, 67, of Tokyo’s Setagaya Ward, Akihiro Hara, 66, of Sakura, Chiba Prefecture, Kiku Nishibe, 64, of Gifu, Gifu Prefecture, and Kyo Ishihara, 59, of Sapporo, Hokkaido.

The car the four were riding in collided head-on with a truck near the city of Maan, some 200 km south of Amman, according to reports received by JICA. The cause of the accident was not immediately known.

Kawatani, Hara and Nishibe were apparently killed instantly. Ishihara underwent surgery for severe injuries at a local hospital and was later transferred by helicopter to a medical facility in Amman, but he died Saturday morning.

The Japanese men were on a sightseeing tour of the country, taking advantage of a three-day holiday that began Thursday. On Friday they were on their way to the Petra ruins in southern Jordan.

The four were dispatched to Jordan in April to carry out two-year assignments on JICA’s senior overseas cooperation volunteer program. The program sends volunteers aged 40 to 69 to developing countries to share their knowledge in various fields.

It is the first time senior volunteers of the JICA program have died while on assignment since the program was introduced in fiscal 1990, JICA said.