"We will activate more helplines to be of further assistance to families and friends of those affected by attack," the Indian High Commission said on Twitter.
"Any Indians injured in Manchester attack today may reach off-office hours of Public Response Unit of HCI (High Commission of India) ASAP at 0207632 3035," it tweeted.
A suicide bomber blew himself up at a crowded venue in Manchester where US singer Ariana Grande was performing. At least 22 people were killed and 59 were injured. The attacker, carrying an improvised explosive device or IED, was also killed at the scene the pop concert at Manchester Arena.
"We have been treating this as a terrorist incident and we believe that while the attack last night was conducted by one man, the priority is to establish whether he was acting alone or as part of a network," Chief Constable Ian Hopkins of Greater Manchester Police said.
The Indian High Commission in London had yesterday organised a community event to mark the Anti-Terrorism Day, coinciding with former Prime Minister Rajiv Gandhi's death anniversary on May 21.
"The scourge of terrorism affects innocent lives not just in one country but across the globe. No country and no people should shelter terrorists, promote terrorists or appease terrorists," Indian High Commissioner to the UK Yashvardhan Kumar Sinha said at the event, during which he led an anti-terrorism pledge.