It was not possible at this stage to identify the terrorists who exploded a bomb outside Delhi High Court Wednesday killing nine people, Home Minister P. Chidambaram said.

Chidambaram told the Lok Sabha that Delhi was a target for terrorists as it was the national capital.

Accordingly, Delhi had been put on high security alert, he said in a brief statement.

The minister said the blast left nine dead and some seriously injured.

"We are clear that there is no cause that will justify the terrorist act," he said.