Rescue workers scrambled yesterday to pull victims from the rubble of a building that collapsed in Thailand's Pathum Thani province.
Three construction workers were killed and more than 20 were injured in the accident on Monday evening, Bangkok Post reported.
"We can't say how many are trapped inside but we are working hard to rescue them," an official told AFP, adding that police will launch an investigation into why the building collapsed.
Witnesses said the building collapsed when the workers were pouring concrete on the top floor of the structure.
Officials said at least 30 workers were trapped in the rubble.
Among the dead was a man whom the officials were trying to supply saline solution and oxygen to. They were planning to amputate his legs, which were trapped under a beam.
The building, which has been under construction for four months, was to be a dormitory for a local vocational college.
Mr Suchatchawee Suwansawad, director of the Engineering Institute of Thailand, said after inspecting the site that factors contributing to the collapse were the building design and the construction materials used. The construction process may not have met the required standards, he was quoted as saying.
He said: "I'm saddened by the building collapse and I see that this incident should not have happened. People are not allowed to enter buildings that are under construction."
Junta spokesman Colonel Winthai Suvaree said the military had been ordered to join the rescue effort.
Labour groups have warned about lax safety standards and low wages at Thai construction sites, especially for migrant workers from Myanmar, Cambodia and Laos, who are often paid below the country's minimum daily wage.
The nation has seen a building boom in recent years as the property market soared.
Meanwhile, the police will charge contractors of the building for negligence causing deaths and injuries, The Nation reported.
Police Major General Smithi Mukdasanit said their licences would be inspected.
This article was first published on August 13, 2014.
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