NEW DELHI  Indian authorities issued security alerts in several major cities on Tuesday evening after a bomb detonated in the Hindu holy city of Varanasi. The police said the explosion and ensuing panic of pilgrims left a toddler dead and at least 20 other people injured.

Indian media reported that police also appeared to have discovered other explosive devices that had not detonated.

India’s Home Secretary, G.K. Pillai, told the Indian press that the blast was a likely terror attack, though he declined to discuss details. A banned terror group, the Indian Muhajideen, claimed responsibility in emails to different Indian media outlets, though authorities were still investigating whether the claim was credible.

“We are collecting more details,” said Braj Lal, a ranking police official in the state of Uttar Pradesh, which includes the city of Varanasi. “A high alert is sounded in the state.”