A red signal was hoisted at Teljana point in Malda district last evening after water in Fulahar river rose to extreme danger level following heavy rainfall.
Villages under the unprotected area including Uttar Vakulia, Kawadole and Rashidpur have been flooded, said Salil Kumar Paul, SDO of Mahananda embankment division affecting at least 15,000 people.
SDO of Chanchal Devjani Dutta said, "At any time the embankment may breach at Valuka point. The administration is keeping a close watch of the situation."
People of nearby four villages were asked last night to move to safer places, she said adding if the embankment breached, the flood water would affect Ratua I, Harishchandrapur II and Chanchal II blocks.
Malda Zilla Parishad sources said work was on war footing at Valuka point to protect the embankment but it was hampered due to continuous rain.