The warning was issued to people living in Phitsanulok, Tak, Phrae, Kamphaeng Phet, Phetchabun, Sukhothai and Uttaradit.

The department said there would be heavy downpours in these areas in the next two days that would saturate the soil with water, increasing the risk of landslides. It urged residents in landslide-prone areas to keep a close eye on forecasts.

In Phitsanulok several subdistricts of Wang Thong district have been submerged as a result of heavy rainfall. Wang Nok An subdistrict was reported as being under one metre of water. A whole house was swept away by a flash-flood into the Wang Thong River. Fortunately, all five people in the house survived without serious injury. The province has seen heavy downpours since Friday night, with Santi Krusuansombat, the deputy provincial governor, ordering authorities to be on standby round the clock..

The Meteorological Department said the heavy downpours were caused by the northwestern and southeastern monsoons meeting over the lower North. It said heavy rain would continue for one or two days more.

Meanwhile in Bangkok, 32 streets were reportedly under water after yesterday's heavy rain. The FM 91 traffic radio station said commuters had reported 91 road accidents which claimed four lives just in the evening, when the downpour reached its peak. The station said 51 drivers had asked for help from the radio station after their cars broke down due to the floodwater.

Traffic on major roads such as Rajdam-noen Klang, Sukhumvit, Phaholyothin, Sirindhorn, Ngarmwongwan, Yaowarat and Vibhavadi-Rangsit was paralysed.