At least 18 persons were killed in lightning strikes in 10 districts of Bihar on Tuesday, even as the Meteorological Department cautioned people not to move about in open places due to fear of lightning and heavy rain in the next 24 hours.Lightning detection centres have been established in Madhubani, Katihar, and Gaya. Teams from the state disaster management authority have been asked to remain on standby.Four deaths due to lightning were reported from Raghavpur block in Vaishali district, two each from Rohtas, Bhojpur and Gopalganj, and Saran districts, and one each from Patna, Begusarai, Araria, Supaul, and Kaimur and another district after heavy rain on Tuesday afternoon.The officials said that over 330 persons had lost their lives due to lightning strikes this year, including 100 on June 24.Officials warned people to stay away from lakes, ponds, trees, and metal poles and to be careful while using electrical equipment with iron and copper parts, and not to sleep on the floor.