British police say a nerve agent was used to try to kill former Russian spy Sergei Skripal and his daughter in the southwestern city of Salisbury.
Iranian authorities have detained an Iranian cleric who recently accused the Iranian establishment of being repressive and unjust.
The Kremlin has confirmed that Russian President Vladimir Putin, Iranian President Hassan Rohani, and Turkish President Tayyip Erdogan will meet for talks during April.
Israeli Prime Minister Benjamin Netanyahu took aim at Iran on Tuesday, saying the Islamic Republic is responsible for "darkness descending" on the Middle East by building an anti-Israel empire.
The U.S. Department of State Spokesperson Heather Nauert has expressed regret over the death of Mohammad Raji in custody, in Tehran.
Iran has increased its missile production three-fold, a senior Revolutionary Guards commander said Wednesday, according to the Fars news service.