KUALA LUMPUR (Reuters) - Malaysia is hunting for an industrial device containing radioactive material that is reported to have gone missing from a pickup truck on Aug 10, police and media said on Monday.

Authorities fear the device, which contains an unknown amount of radioactive iridium, could cause radiation exposure or be used as a weapon by militants, the New Straits Times daily said, citing unnamed sources.

The 23-kg (51-lb) device, used in industrial radiography, went missing on a journey to Shah Alam, on the outskirts of Kuala Lumpur, the capital, from the town of Seremban, about 60 km (37 miles) away, the paper added.

“Yes, there is a report and we are investigating,” Mazlan Mansor, police chief of the surrounding state of Selangor, told Reuters in a brief text message. He declined to elaborate.

Two employees of the firm that owned the missing equipment were arrested but later released because of insufficient evidence, media said.

Any loss or theft of radioactive material could put it in the hands of militants who might try to build a crude nuclear device or a so-called “dirty bomb”, the United Nations atomic agency has warned.

Such a device combines nuclear material with conventional explosives to contaminate an area with radiation, in contrast to a nuclear weapon, which uses nuclear fission to trigger a vastly more powerful blast.