SAN FRANCISCO, Jan 30: The United Airline domestic terminal at San Francisco International Airport was evacuated for 90 minutes on Wednesday after explosive residue was discovered on a man’s shoes, and the man went missing, an airport official said.

Airport spokesman Mike McCarron said flights were held at 30 gates as authorities searched for the suspect. Thousands of passengers who were evacuated from the building were being slowly re-screened by security personnel and allowed back in, he said.

McCarron said security officials found the residue on the shoes about 1515 GMT, “but when they turned to talk to the man, he had gone into the crowd”.

McCarron said the Federal Aviation Administration ordered the gates closed and the flights held after it was advised of the incident.

Air passengers have had their shoes scrutinized closely since British Muslim Richard Reid was arrested last month in Boston for allegedly attempting to blow up a transatlantic jetliner by detonating explosives hidden in his shoes. Reid has pleaded not guilty to all nine charges filed against him.

Stepped up shoe security includes making passengers remove their footwear for inspection, as well as swabbing soles with wipes that can detect explosive residue.

The man, described as being in his mid-40s and white, was wearing his shoes when he disappeared.—AFP