BANGKOK (Reuters) - Thailand's capital was braced for more flooding on Sunday as water levels rose in some of Bangkok's northern suburbs and troops raced to fortify defense walls to protect two key industrial zones.
Authorities have taken measures to divert floodwaters flowing from the north away from the city and into the Gulf of Thailand, but the capital was on tenterhooks because of the possibility of heavy rainfall into canals and rivers already full to the brim.
Prime Minister Yingluck Shinawatra said authorities were doing everything possible to drive the water out, but were facing a race against time.
"Water is coming from different places and headed in the same direction. We're trying to build walls but there will be some impact on Bangkok," Yingluck told reporters, adding that high tide in the Gulf by the end of the week could complicate the situation.
Thailand's worst flooding in half a century has affected a third of the country and has been bearing down on Bangkok since early last week.
Twenty-eight of 77 provinces and 2.46 million people are affected, with water covering an area the size of Kuwait. Yingluck said on Saturday it could take as long as six weeks for the water to subside.
Since late July, 356 people have been killed and at least 113,000 moved to more than 1,700 makeshift shelters.
The full force of the flooding has hit central provinces and those on the edge of Bangkok, where water levels have reached as high as three meters, with vehicles completely submerged and some residents believed to be stranded in their homes.
The northern Bangkok districts of Don Muang and Lak Si were inundated on Sunday after spilled out of the Prapa canal. Boats and cars were seen side by side on a main road, with people seen wading through water or boarding trucks for evacuation as water levels were up to two meters in some parts.
Thai television showed footage of a two-meter long crocodile caught by authorities in a residential area.
Fears rose as water levels in the vast Chao Phraya River flowing through Bangkok were at a seven-year high and a flood wall collapsed next to a school on the banks. Some 1,200 people in riverside shanty towns were advised to leave their homes.
Deputy Prime Minister and Commerce Minister Kittiratt Na-Ranong said the Don Muang airport, which has been turned into an evacuation center, would be used to provide food and water supplies from Monday to address shortages in the city.
Bangkok was sunny on Sunday, although the Meteorological Department has forecast scattered rain.
The government's flood agency said late on Saturday some toxic chemical had been found in floodwaters in Pathum Thani province and the Pollution Control Department was assessing the impact.
The crisis is likely to take a heavy toll on the export-driven economy, Southeast Asia's second-biggest, with supply chains severely disrupted by blocked roads and the closure of seven swamped seven industrial estates in Pathum Thani, Nonthaburi and Ayutthaya provinces bordering Bangkok.
Growth might be about 3 percent rather than the 4.1 percent forecast earlier, the central bank said. The finance minister has said it may not even top 2 percent this year.
Troops were raising levels of flood walls to protect Lat Krabang and Bangchan industrial zones to the north and east of the city but army chief Prayuth Chan-ocha said on Saturday he could not guarantee they would not be breached.
Lat Krabang hosts 254 factories -- 49 of them Japanese -- while Bangchan has 90. Both are responsible for autos, transport, food and beverage and electrical appliances industries.
Honda, Isuzu Motors and Unilever are among the firms operating at the two estates.
(Additional reporting by Jutarat Skulpichetrat and Pisit Changplayngam; Writing by Martin Petty; Editing by Sugita Katyal)