A baby girl, 18 months old, has been killed and at least 25 people have been injured in a blast on the ghats of Varanasi; four are reported to be in critical condition. A railing collapsed in a stampede that followed the blast, contributing to the injuries. (Watch: Varanasi blast caught on camera) PTI reports an Improvised Explosive Device (IED) has been recovered from a dustbin at the blast site.In New Delhi, Secretary (Internal Security) U K Bansal said the explosion was a "medium intensity" blast.In an e-mail to some media organizations, a group claiming to be the Indian Mujahideen has claimed responsibility. However, the government says investigations are on.Karamvir Singh, the state's Director General of Police, reached Varanasi late Tuesday night. He said the police is taking the Indian Mujahideen e-mail seriously and following up all leads.Singh added preliminary investigation suggests the explosive was kept in the wall between two ghats. A forensic report is expected in 24 hours, he said.The explosion took place at, near the main ghat where dailyor prayers are offered. The blast took place just as theended.The Prime Minister has asked the Home Ministry for a report, and has appealed to people to stay calm. (Read: PM seeks detailed report from home ministry)

Police has been put on high-alert in all towns and cities of Uttar Pradesh. Delhi, Mumbai , Hyderabad and Bangalore are also on alert. (Read: Delhi on high alert) The MP from Varanasi, the BJP's Murli Manohar Joshi, said, "Security must be strengthened at the ghats because many foreigners come to visit especially in this month." (Watch)