Seven persons ,including five children ,were killed and eight injured in a LPG cylinder blast here on Wednesday this afternoon. The incident took place while wedding preparations at the house of a man named Lallan were on in Rafipur village under Deva police station area. The small cylinder exploded injuring 15 persons, police said. The injured were shifted to Civil Hospital in Lucknow where Sonam (3), her brother Aditya (4), Khushi (3), Golu (4), his brother Vivek (3), Gyanwati (45) and Kalawati (60) succumbed, police said.