A Malaysian worker was killed in the Algerian hostage crisis and one of his colleagues at the north African desert oil gas complex is still unaccounted for, the foreign ministry said Wednesday.

The ministry is working with the operator of the facility to fly the body of the man identified as Chong Chung Ngen back to Malaysia, it said in a statement.

But Foreign Minister Anifah Aman said the government was concerned over the lack of details from Algerian authorities in its efforts to locate the missing man, Tan Ping Wee.

“Furthermore, the official statement issued by the Algerian authority has not stated details of the rescue operation as well as the complete list of missing hostages,” he said.

Two other Malaysians working at the plant have been moved to Algiers where they are waiting to fly home while one of their colleagues has volunteered to stay and help locate Tan.

Thirty-seven foreigners of eight different nationalities and an Algerian were killed in the siege by the hostage-takers, who were demanding the release of Islamist prisoners and an end to France’s intervention in Mali.

Algerian authorities searched on Tuesday for five foreigners still missing and tried to identify seven charred bodies, days after the crisis ended, a security source said.