Extremely heavy rainfall measuring up to 28 cm in certain parts returned to lash coastal and south Karnataka districts, disrupting normal life after a brief lull last week, the weather office said on Monday.
"The southwest monsoon has been active over coastal and south interior Karnataka, while also causing light to moderate rainfall in north interior districts of the state," the Bengaluru division of the India Meteorological Department (IMD) said.
Heavy rains flooded several low-lying areas of Dakshina Kannada, Uttara Kannada, Udupi, Kodagu and Chikkamagaluru districts, which received heavy to very heavy rainfall up to nearly 20 cm, leading to overflowing rivers and lakes.
The rains claimed the lives of four people, including two women, over the weekend in Dakshina Kannada and Chikkamagaluru districts.
There were reports of damages to roads and bridges in the districts causing hardship to commuters.
Fishermen have been advised by the state authorities to avoid venturing into the Arabian Sea due to heavy winds.
According to IMD, Mulki in Dakshina Kannada district, about 370 km west of Bengaluru, received the highest rainfall in the state as on Monday, recording 28 cm on the rain gauge.
Parts of port city Mangaluru in Dakshina Kannada district received heavy rainfall of about 16 cm and pilgrim town of Bhagamandala in Kodagu district received 14 cm of rainfall as on Monday.
Several state-run schools and colleges remained closed on Monday, officials said.
Teams of the National Disaster Response Force (NDRF) have been deployed in the coastal districts of the southern state and have been rescuing people stranded in the waterlogged areas of the coastal region.
With water entering several houses in Udupi district, families were shifted out of their homes to high-altitude areas.
The copious rains have been filling the reservoirs in the Cauvery basin.
Kabini reservoir in Mysuru district, one of the major tributaries of Cauvery river, has been filled to its maximum capacity of 2,284 feet (696 metres) due to the heavy monsoon.
The Krishna Raja Sagara (KRS) reservoir built across Cauvery in Mandya district has received water up to 110 feet of its total capacity of 124 ft.
Other reservoirs of Hemavathi (across Hemavathi river in Hassan district), Tungabhadra (across Tungabhadra river in Ballari district) and Harangi (across Harangi river in Kodagu district) have also reached their maximum limits with heavy rains in the catchment areas.
Water from some of the dams, filled to their maximum limit, is being released, flooding the areas along the course in the south interior districts.
Karnataka has been releasing excess water from its reservoirs to neighbouring Tamil Nadu after the rains led to filling of the state's dams within three weeks after the onset of southwest monsoon on June 4.
Since the southwest monsoon set in the state, districts of Udupi, Dakshina Kannada, Uttara Kannada have received an excess rainfall of about 10 per cent till date.
South interior districts received an excess rainfall with Kodagu receiving 24 per cent, Hassan 56 per cent and Chikkamagaluru 32 per cent.
North interior districts of Vijayapura, Gadag, Haveri and Raichur continue to face deficit in rainfall.
The rains, however, are expected to continue over the coastal and southern districts of the state for the next few days, IMD added.