Three people were arrested in England on Thursday in connection with the stabbing of an Indian general who was visiting London.
Lieutenant-General Kuldeep Singh Brar, 78, was attacked by four men in Old Quebec Street, near Oxford Street, on Sunday night.
The Metropolitan Police said two men and a woman in the West Midlands are under arrest on suspicion of conspiracy to murder.
General Brar was taken to hospital with a neck wound and has since been discharged. He described the stabbing as an assassination attempt.
The BBC reports he led a raid in 1984 on the Golden Temple in Amritsar in Punjab state. Hundreds died when the troops entered the temple, Sikhism's holiest shrine.
General Brar is thought still to be a target for extremist Sikhs, but the identity of his attackers is unclear.
