Thiruvananthapuram, Nov 30 : A 'red alert' has been issued in Kerala's southern districts of Thiruvananthapuram, Kollam, Pathanamthitta and Alappuzha, and 'orange alert' in Kottayam, Idukki and Ernakulam districts till Thursday owing to predictions of inclement weather conditions. Kerala has also banned all fishing activities starting Monday midnight till further notice. Authorities have asked all those out fishing in the sea to get back to the nearest coastal zone. The Kerala State Disaster Management Authority action follows development of a low pressure area over south Andaman Sea and adjoining areas of south-east Bay of Bengal that is likely to concentrate into a depression in the next 36 hours and reach south Tamil Nadu coast around Wednesday. Weather officials have predicted moderate to heavy rains starting Tuesday till Friday in the state. Strong winds are also expected to hit the state, especially the southern districts. /IANS