A man was arrested on Thursday in Whitehall in London, near the Houses of Parliament, for possession of weapons, following a stop and search procedure “as part of an ongoing operation”, Metropolitan Police said. The area has been blocked off by police personnel.

The man, in his late twenties, was detained in Parliament Street, the police said. Knives were recovered from him and he has been detained under the Terrorism Act. “As a result of this arrest there is no immediate known threat,” the police said.

On March 22, a man had mowed people down with his vehicle on the Westminster bridge while heading to the Parliament building. At least 40 others were injured in the incident. The assailant was later identified as Khalid Masood, a 52-year-old Central England resident. Counter-Terrorism Commander Mark Rowley had said that the assailant’s birth name was Adrian Russell Ajao.