At least three people were killed and about 75,000 people were driven out of their homes as monsoon rains lashed Sri Lanka on Monday, the disaster management centre said. Some roads in the capital and in worst-hit central and southern Sri Lanka have been rendered impassable, the centre's assistant director Pradeep Kodipillai said. Since Sunday, electricity supplies to main towns outside the capital have been disrupted due to trees falling on power lines. Several roads in Colombo have been submerged as a result of the heavy rain Monday. The roads include Barney Raymond road, the Ibbangala junction and the Library roundabout, police media spokesman Preshantha Jayakody said. The Department of Meteorology says a storm is developing over Sri Lanka and this is the cause of the heavy rain and strong winds being experienced in many parts of the country since Monday morning. Meanwhile, a landslide warning has been issued for parts of Ratnapura, Kalutara and Galle as heavy rain continued to lash the island with strong winds. The authorities have urged residents in these areas to take precautions. At least three flights scheduled to arrive and depart Sri Lanka Monday morning were disrupted as a result of the ash clouds over Europe and inclement weather conditions over Sri Lanka. The duty manager at the Bandaranayaka airport said that one flight scheduled to depart for Europe Monday morning had cancelled as a result of some airports in Europe being closed owing to the ash clouds emanating from a volcano in Iceland. Meanwhile at least two flights scheduled to arrive in Sri Lanka had diverted to India as a result of the inclement weather conditions over Sri Lanka. Sri Lanka depends on monsoon rains for irrigation and power generation but the seasonal downpours frequently cause loss of life and damage to property in low-lying areas. The island's two main monsoon seasons run from May to September and December to February.