New Delhi, Feb 25 (IANS) Pakistan should investigate the claims of unknown militant groups that had owned responsibility for the Feb 13 Pune bombing, Indian Foreign Secretary Nirupama Rao told her counterpart Salman Bashir Thursday.

'(The) recent Pune attack is yet another reminder that our citizens are vulnerable to terror activities,' Rao told reporters after her talks with Bashir here.

'We went with an open mind but fully conscious of our concerns,' Rao said.

She said Pakistani officials were asked to 'investigate the claims of hitherto unknown group Lashkar-e-Taiba Al Alami (besides) Illyas Kashmiri'.

A person identifying himself as spokesperson of the Lashkar-e-Taiba Al Alami, a breakaway faction of the Lashkar-e-Taiba (LeT), had called an Indian journalist in Islamabad and owned up the Pune bombing that killed 16 people.

Illyas Kashmiri, an Al Qaeda leader in Pakistan, is known to have links with LeT operative David Coleman Headley who is currently in US custody.

Kashmiri has threatened to target upcoming major sporting events in India.