LONDON (Reuters) – British police announced on Sunday a second arrest in connection with an assault on three police officers by a man armed with a four-foot sword outside London’s Buckingham Palace on Friday.

A 30-year-old man was arrested at an address in West London on suspicion of being “involved in the commission, preparation or instigation of terrorism,” police said.

A man deliberately drove at a police van close to the Queen’s official residence in London late on Friday and was detained by three police officers, who sustained minor injuries.

A 26-year-old arrested at the scene remains in custody after a warrant for his detention until Sept. 1 was granted, the police said.