Media playback is unsupported on your device Media caption Survivors are rescued from the rubble

A seven-storey building has collapsed in Cambodia, killing at least 18 people with others reported missing, officials say.

At least 24 people have been injured - several critically - as the search for survivors continues.

The building under construction in the coastal city of Sihanoukville was owned by a Chinese company.

In recent years, Sihanoukville has been transformed by the construction of Chinese hotels and casinos.

Four people have been arrested over the collapse, including the Chinese building owner, the head of the construction firm and the contractor. A Cambodian landowner has also been taken in for questioning.

Reports vary on the number of people missing as rescue efforts continue.

Image copyright Reuters Image caption A rescue team carries a wounded worker from the collapsed building in Sihanoukville.

Three of the victims have been confirmed as Cambodian - two workers and a translator.

About 1,000 people contributed to a rescue effort which involved using saws to cut steel beams in order to move piles of rubble from the site.

Construction workers told the Associated Press that they were also living in the building.

"A moment before the building collapsed it was vibrating and then it was falling down," Nhor Chandeun told the news agency. "But it was too quick to escape."

"My wife and I kept calling for help," he said. "We were shouting and shouting but there was no sound replying to us and we presumed that we would die under the rubble."

Both he and his wife were rescued after 12 hours of being trapped.

The provincial governor said about 50 workers would usually be on site at the time the building collapsed.

The building collapse - the worst of its kind in Cambodia in recent years - will raise further questions over the rate and sustainability of construction in Sihanoukville.

It is also likely to add to rising anti-Chinese sentiment in the country, correspondents say.

The once-small fishing village saw a boom in tourism in the 2000s, but the last three years has seen the area change beyond recognition with the construction of dozens of casinos catering almost solely to Chinese tourists.

Cambodia has notoriously lax labour laws, putting construction workers at risk.

The International Labour Organization has highlighted the "exposure of workers to constant safety and health hazards" on building sites.