Bengaluru,  With the southwest monsoon turning vigorous, the weather office on Friday issued a red alert, warning of extremely heavy rainfall in three coastal districts of Karnataka over the next 48 hours.

"Red alert means extremely heavy rainfall to occur in Dakshina Kannada, Udupi and Uttara Kannada districts over the next two days," a Meteorological Department official told IANS here.

An orange alert has been sounded in the districts of Chikkamagalur, Hassan, Kodagu and Shivamogga in the Malnad region where heavy rains are predicted during the weekend.

Moderate to heavy rainfall has been forecast with gusty surface winds in the state's south interior and north interior parts on Saturday and Sunday.

According to the weather bulletin, due to heavy to very heavy rainfall, 21 cm was recorded at Bhagamandala in Kodagu district during the last 24 hours, followed by 18 cm at Kottigehara in Chikkamagaluru district, 15 cm at Agumbe, 13 cm at Thalaguppa in Shivamogga district, and 12 cm in Honnavar and Siddapura in Udupi district.

"Incessant and widespread rains in the coastal, southern and Malnad regions disrupted normal life, as rivers and their tributaries flooded roads and bridges, inundated low-lying areas in villages and uprooted trees and electric poles," said the official.

Fishermen have been advised against venturing into the sea on the next two days due to strong winds up to 50 kmph speed and high waves up to 5 metres from Mangaluru to Karwar.

Meanwhile, Chief Minister B.S. Yediyurappa directed officials in the rain-hit districts to take preventive measures to protect people from flooding and rain-water entering their houses.

"I will assess the situation and preparations with officials of 20 districts through video-conferencing on Saturday," he said.