New York  - A UN special enjoy to Niger has gone missing while driving outside the capital, Niamey, UN Secretary General Ban Ki-moon said.

Canadian Robert Fowler, a Canadian colleague and their driver went missing Sunday, the United Nations said Monday. Their empty car was found with its motor still running.

A UN spokesman said Monday that there was no trace of the three passengers and no indication that they had been taken hostage in the West African country.

"We are doing all our best efforts about his whereabouts," Ban said. "We are now mobilizing all necessary information networks on this."

Niger security forces were also looking for Fowler, whom Ban named his special envoy in July. (dpa)