According to officials, half a dozen districts of flood-hit north Bihar are likely to receive 90 mm to 135 mm of rainfall in the next 24 hours.
An official of the water resources department said heavy rainfall is likely in Madhubani, Sitamarhi, Purnea, Araria, Katihar and Kisganganj districts. Besides, rain is expected in Supaul, Siwan, Darbhanga, Madhepura, Muzaffarpur and East and West Champaran.
"It will certainly increase the water level in rivers and flood situation will worsen".
Meanwhile, the disaster management department said relief and rescue operations were continuing in the flood-affected areas. A total of 20 companies of the National Disaster Response Force and the State Disaster Response Force have been deployed in the area.
Over 72 lakh people in 104 blocks in 12 districts have been affected by the floods that have claimed 102 lives so far.
More than one lakh people have been displaced, with 1.14 lakh taking shelter in 133 relief camps of which 127 have been set up in Sitamarhi, one of the worst flood-hit districts in the state.
Hundreds of villages have been inundated, forcing people to leave their homes and seek shelter at safer places, a disaster management official said.
The floods were caused by heavy rain in north Bihar and the catchment areas of major rivers in neighbouring Nepal.
( With inputs from IANS )