Thailand, Nov 06, 2008 - Seasonal flooding has left four people dead in central Thailand as more than a week of heavy rains has brought several major rivers over their banks. All four victims drowned in Ayutthaya province, where the government says four districts are being affected by floodwaters as deep as 6.6 feet (two meters) in some areas. Dozens of schools have been closed and at least 33 have flooded. Officials have been forced to release large amounts of water from major dams upstream of Ayutthaya that had reached their capacity and were at the same level as two years ago, when central Thailand suffered its worst seasonal floods in about a decade. The release of water earlier this week has caused a rise in the Chao Phraya River, the major system that passes through central Thailand, causing floods in Ayutthaya and neighboring Angthong, Sing Buri and Lop Buri provinces. Ayutthaya's Irrigation Department said Thursday (November 6) that the surge of upstream waters has caused a major increase in the rate of flow at one key Chao Phraya dam and if the water moves much faster, there could be flooding in the capital, Bangkok, the Bangkok Post reported. The Noi, Lop Buri and Pasak Rivers are also on the brink of overflowing, Bangkok-based The Nation reported the Disaster Prevention and Mitigation Department as warning. The Thai Ministry of Public Health has dispatched 20 mobile medical units to help flood victims in Ayutthaya, Nakhon Ratchasima, Nakhon Sawan, Ang Thong, Kamphaeng Phet and Chaiyaphum provinces. In Sing Buri province, the Red Cross is leading efforts to distribute survival bags to flood victims. Thailand's southwestern monsoon season typically runs from May through October. Although in 2006, 46 of 76 provinces flooded and about 40 deaths were reported, both last year's season and this year's have been relatively mild.