Indian authorities say a terrorist attack outside the Indian high court in New Delhi killed at least 11 people and injured 66 others. Police believe the explosive was placed inside a briefcase near a main gate to the high court in New Delhi. The blast is being described as a "medium-intensity bomb." Injured were rapidly transported to area hospitals and police cordoned off the area to begin an investigation. Speaking from Bangladesh, Indian Prime Minister Manmohan Singh was quick to label the explosion an act of terror. "This is a cowardly act of a terrorist nature... All the people of India have to stand united so that the scourge of terrorism is crushed," he said. Indian Home Minister P. Chidambaram visited the bomb site and says top national investigation teams are examining evidence. "At this stage, it is not possible to identify the group that caused the bomb blast," he said. There have been no claims of responsibility. Chidambaram reminded lawmakers that New Delhi is a target of terrorist groups, especially when parliament is in session. "We shall never be intimidated by terrorist groups," he said. "We are determined to track down the perpetrators of this horrific crime and bring them to justice." In New Delhi, there have been 15 bombings since 1997. For many, Wednesday's explosion also called up fresh memories of July's serial bombing in the southern Indian commerce capital, Mumbai, which killed 20 people.