Tel Aviv/Tehran, June 19 -- The Israel-Iran conflict threatened to snowball on Thursday with both countries intensifying missile attacks against each other, and Israeli Defence Minister Israel Katz issuing a stern warning to Iran's supreme leader Ayatollah Ali Khamenei saying he can ''no longer be allowed to exist". The warning came after Iran launched a missile attack on Israel. One of the missiles struck a hospital in southern Israel. The hospital, Saroka Medical Center, is the largest hospital in Southern Israel. About 50 people were reportedly injured in the attack. Israel struck Iran's nuclear site Arak heavy water reactor. However, Iran denied that any of its missiles had hit a hospital and said it was an Israeli military base and in...