Soldiers plucked stranded homeowners from chest-deep water and floods threatened major manufacturing plants in central Thailand as international firms raised alarm over authorities' ability to handle the inundations.

Heavy rains have swept the kingdom in recent days, with the worst of the flooding concentrated in central and eastern provinces where international factories have been waterlogged in a development that has raised parallels with devastating inundations two years ago.

"We have not received any help from the government -- we are disappointed with them," said a member of the management team at a subsidiary of Japanese electronics and auto giant Mitsubishi, whose plant at in Chonburi province's Amata Nakorn Industrial Estate is one of several surrounded by water.

"We cannot calculate the losses right now," she told AFP, asking not to be named, but added that the factory had been shuttered for three days and some 800 employees had been sent home on full pay.

Some 37 people have died so far in this year's floods and around 1.7 million people have seen their homes or businesses waterlogged.

Floods around 1.5 metres deep were seen by an AFP photographer in the town of Kabin Buri in Prachin Buri province, one of three severely affected regions in central Thailand.

Authorities said the army had been drafted in to move, evacuate and transport local people.

Thailand's 2011 deluge, which were concentrated further north than the current floods, took a heavy toll on its lucrative manufacturing base, disrupting global supply chains and causing a double-digit contraction in the economy.

Output has since recovered strongly, but the country has remained nervous over the potential of a repeat.

Viboon Kromadit, of the Amata Corporation Public Company, told AFP that there was only a small amount of water in the vicinity causing minor inconvenience to firms.

But Mitsubishi said its factory was surrounded by knee-high floods that have reached the top of sandbag defences.

Thai television reports also quoted Peter Coates, the managing director of Triumph Motorcycles in Thailand, which also has a factory in the Amata estate, criticising the flood response.

"It needs to be managed, it is not being managed," he said.

The country's National Disaster Warning Center has cautioned over expected high sea levels next week, but said the capital will not be waterlogged.

"It is a warning not a crisis -- I confirm Bangkok will not be flooded," the centre's director Somsak Khaosuwan told AFP.