In the 1980s and 1990s, Islamic militancy in pursuit of religious and political goals increased, many militants drawing inspiration from Iran's 1979 Islamic Revolution. In the 1990s, well-known violent acts that targeted civilians were the World Trade Center bombing by Islamic terrorists on February 26, 1993, the Sarin gas attack on the Tokyo subway by Aum Shinrikyo on March 20, 1995, and the bombing of Oklahoma City's Murrah Federal Building in April 1995. Religion was a main factor in most cases. Single issue terrorism was use by organized pressure groups of violent action, as in Anti-abortion terrorism and Environmental terrorism.