New Delhi, Sep 7 (IANS): At least four people were killed and 25 injured in a blast outside the Delhi High Court Wednesday morning, officials said. The explosion took place outside Gate No 5 on a busy weekday morning.

"At least four people have lost their lives in the blast," Special Secretary Home U.K. Bansal told a news channel.

Police said the bomb may have been kept in a briefcase around the security counters near Gate No. 5 from where security passes are issued to visitors.

"There is a possibility that the bomb was kept in a briefcase. We have cordoned off the area and are requesting people to not converge here," Special Commissioner of Police (Law and Order) Dharmendra Kumar told reporters.

Though police said 25 people had been injured, eyewitnesses said the number was closer to 50 or 60.

According to an eyewitness, Bhagwan Das: "The explosion severed the limbs of several people."

This is the second blast targeting the Delhi High Court in four months.