Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. A second man has been held on suspicion of terrorism offences amid fears a man seized at Buckingham Palace with a sword was not a ‘lone wolf’, but part of a network.An unnamed 30-year-old was held at a West London address “on suspicion of being involved in the commission, preparation or instigation of terrorism”.The arrested man is believed to have been in recent contact with a 26-year-old man arrested outside Buckingham Palace late on Friday. Second arrest in west London following Constitution Hill terror incident https://t.co/x3etPfp2kr pic.twitter.com/dTQ7XZ8V6t— Metropolitan Police (@metpoliceuk) August 27, 2017 That man from Luton was seized after he drove at police before lunging for a 4ft sword and repeatedly shouting “Allahu Akbar”.The man was wrestled to the ground by unarmed police who had to use CS gas to incapacitate him.During the struggle three officers were injured, two of whom suffered minor cuts to their hands and required treatment in hospital before being discharged.The attacker is also being held under terrorism legislation and a warrant for his further detention was granted on Sunday.Scotland Yard initially said they were not seeking anyone else in connection with the attack, but then announced they had held another suspect on Sunday morning.Sources said police and counterterrorism officials had worked round the clock to see if the man had accomplices, or if anyone had known of his intentions before the alleged attack. Commander Dean Haydon, of the Met’s counter-terrorism branch, said the attack near Buckingham Palace had seen a blue Toyota Prius deliberately drive at a marked police vehicle.The car stopped in front of the police car and when police confronted the driver, he reached into the passenger footwell for a four-foot sword.Police used CS gas to subdue the man, who repeatedly shouted “Allahu Akbar!” during the struggle.Theresa May has praised the bravery of the officers, saying they “acted quickly and bravely to protect the public”.