Angry over the attack on Ramdev, his followers on Monday gathered outside Congress headquarters here and threw black ink on Sonia Gandhi's poster, triggering a clash between Congressmen and supporters of the yoga guru.

Some people under the banner of Yuva Bharat Kisan Panchayat gathered outside the Congress headquarters at 24, Akbar Road to protest the throwing of ink on the yoga guru here two days ago.

They shouted slogans against party chief Sonia Gandhi and leaders Rahul Gandhi and Digvijay Singh and said they will not allow anyone to defame religious leaders.

Some of the protesters then threw black ink on a poster with Sonia's image.

On Saturday, Kamran Siddiqui, who runs an NGO, had thrown black ink at Ramdev during a press conference when the yoga guru evaded his question on Batla House encounter.

As the protesters were there for 5-10 minutes, some Congress workers came out of the premises and entered into an argument with them leading to a scuffle. The police then intervened and brought the situation under control.

Following the incident, more police personnel were rushed to the spot which is next to Sonia's residence at 10, Janpath.