Heavy and widespread rains and rising levels of rivers pose a flood threat in north Karnataka, an official said on Monday."As the southwest monsoon intensified and advanced into the state, heavy rains have been lashing the coastal, central and northern regions for the last 2-3 days, resulting in rising waters in rivers and flood threat to towns and villages in a dozen districts," the State Disaster Management Centre official told IANS here.Incessant rains in the Western Ghats across Maharashtra and Karnataka's northwest region led to overflowing of Krishna river and its tributaries, submerging roads and bridges and disrupting normal life in the inter-state border areas."The overflowing Krishna and its tributaries Malaprabha, Ghataprabha, and Markendya across the inter-state borders have flooded many villages on their banks and other low-lying areas," said the official.Belagavi, Bagalkot, Vijaypura, Dharwad, Gadag, Raichur, and Kalaburgi districts have been inundated by rainwater, overflowing drains, and canals. Thousands of acres of farmland has been inundated.A landslide near Khanapur in Belagavi district disrupted train services on the Hubli-Londa route as the tracks were blocked by debris.About 2.6-lakh cusecs of water has been released since Sunday night into the Krishna river from the Basavasagar dam in Yadgir district to avoid floods in the state's northern region.With forecast of more heavy rains across the state during this week, the Meteorological office has issued an 'orange alert' to ensure the safety of people living along the rivers and their catchment areas.As strong winds with speeds up to 40-50 kmph are likely to prevail along and off the state's west coast, the Met office warned fishermen against venturing into the Arabian Sea as high waves are expected to rise over the next 2-3 days."Heavy to very heavy rains or thundershowers will occur at most places across the coastal, south interior, and north interior areas of Karnataka over the next 48-72 hours," the official said.As the monsoon was vigorous over north and active over coastal areas, 23cm rainfall was recorded in Hosanagara, 21cm in Kolluru, 19cm in Siddapura, 17cm in Agumbe, 15cm in Belagavi, and 14cm in Manki over the last 36 hours.