About 40 people were injured in the attack, of whom 29 remain in hospital, seven in critical condition. Four people, including the attacker, died.
"She has signed the book of condolence and she has recently returned to Number 10 (official residence) after a private visit to a hospital where she spent around 40 minutes speaking with victims of yesterday's events, ward staff, clinical staff ... to thank them for their work," the spokesman told reporters.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.