On ATS radar,a teen with travelling bag

The official stressed that it would be premature to treat the information about the boy as a clue or breakthrough. They were checking it out like a lot of other information,he said.

In the past 48 hours,the investigators have examined hundreds of photographs,a video shot by a tourist,and questioned hundreds of people and scoured the blast site several times,but are yet to make a breakthrough.

Investigating agencies are also scanning phone calls made to Pakistan and Nepal from Mumbai and Uttar Pradesh immediately before and after the incident.

Besides the Uttar Pradesh ATS,the IB,NIA,Mumbai Police,Maharashtra ATS and several other agencies are involved in the investigation. A team from Gujarat police is arriving in Varanasi on Friday.

The UP ATS has questioned some PCO operators in Varanasi and Azamgarh. They have also questioned labourers who were hired for renovation work at the Dashashawamedh Ghat last month ahead of the Bhavya Deepwali Mahotsav on November 21.