The department said heavy rain in the North and upper Central regions had caused water flowing through Ayutthaya's Bang Sai district to reach 3,338 cubic metres per second and that the land flanking the Chao Phya River could no longer serve as natural water-collecting "monkey-cheek" areas.

This, combined with spring tides between October 9 and 13, will lead to the Chao Phya between Chai Nat and Samut Prakan rising higher than normal, especially affecting low-lying areas in Pathum Thani, Non-thaburi and outside the flood barriers of Bangkok, the department said.

Following a Supreme Command suggestion that the department release less water or even stop for three days prior to the spring tides, deputy director-general Peerapong Suwanmontri said the department could not stop releasing water but would keep the release from dams under 3,500 cubic metres per second.

He said the volume of water would not reach 4,200 cubic metres per second as happened in the major floods of 2002.

Meanwhile, Bangkok Governor Apirak Kosayodhin said the city had strengthened the three-metre-high barriers along a 57-kilometre stretch of the Chao Phya with more sandbags and would build sandbag walls up to 2.5 metres in height at other areas beyond.

At the same time, the Public Health Ministry reported that some 3,000 people were falling ill from water-borne disease each day and that the number of patients had reached 134,602, of whom nearly half suffered rashes and symptoms of hand, foot and mouth disease.

In Lop Buri, the Pasak Cholasit Dam contained 39 million cubic metres more than the recommended capacity of 960 million, and was set to increase its water release later yesterday from 32 million cubic metres per day to 40 million.

In the eastern province of Chantaburi, about 900 inmates were evacuated from the central prison and sent to prisons in nearby provinces after the prison's compound was inundated by more than two metres of water.

They were sent to Trat, Rayong, Chon Buri and Pattaya.

With Chantaburi already under water, the city was warned to brace for more flooding later last night due to the spring tide.

Dismissing a rumour of a dam burst, Governor Panas Kaewlai said Khao Khitchakood district's Pluang Dam and Makham district's Khiri Than Dam were strong and that Pluang Dam could hold 14 million cubic metres more water.

Flooding affected 1,200 families, damaged 17,000 rai of farmland and killed two people, one in Na Yai Arm and the other in Makham, Panas said.

Flooding continued to ravage central Angthong province with the Muang district submerged and many roads impassable.

Riverside homes in the provincial capital were under three metres of water. Four people were reported to have drowned yesterday, two in Pa Moke district and two others in the town.

However, locals maintained their religious duties, using boats to make merit to mark the end of Buddhist Lent yesterday.

Angthong's 202 villages and 12,424 rai of farmland, worth Bt62 million, in six districts were flooded, and more areas will be submerged as barriers are breached, said Governor Wiboon Sanguanphong.

Wiboon urged people wanting to make donations to flood victims to call the provincial disaster-prevention centre on (03) 561 6260.

In Ayutthaya's Sena district, the rising Chao Phya and Noi rivers caused breaches at many areas along the concrete barriers. The resulting floods submerged Ban Pan market and residents homes, prompting the authorities to cut electricity at 3am.