London Bridge terrorists may have had siege plans: Police

British police today released images of the fake suicide belts made out of plastic bottles strapped on the three London Bridge attackers and said the terrorists, one of whom was born in Pakistan, may have had plans to take hostages.

The Metropolitan Police officer leading the investigation said the use of belts that were later established as fake was a tactic he had not seen before in the United Kingdom.

"I have not seen this tactic in the UK before where terrorists create maximum fear by strapping fake explosives to themselves. Anyone who saw them on the night would have thought they were genuine," said Commander Dean Haydon.

He said it was hard to speculate the exact reasoning behind the belts, but they may have been intended to take hostages or as a defensive strategy.

"It could be that they had plans to take the attack into a siege situation or it might be that they saw it as protection from being shot themselves," the officer said.

Pakistan-born Khuram Shazad Butt, Moroccan-origin Rachid Redouane and Moroccon-Italian Yousef Zaghba claimed eight lives when they mowed down pedestrians on London Bridge and then went on a stabbing spree before being shot dead by police on June 3.

The photos of the suicide vests were released a day after police revealed that the attackers had tried to hire a 7.5 tonne lorry to run people over on London Bridge during the attack.

The men failed to provide payment details and the vehicle was not picked up, prompting them to use a smaller van from a DIY store instead.

It has since emerged that Butt, the British Pakistani ringleader, had also attempted to get a job with a security firm in charge of safety at Wimbledon tennis court and football clubs in London.

Since the attack last week, 20 people have been arrested, 13 buildings searched and seven people remain in custody.

The police said they have questioned 262 witnesses from 19 countries – of which 78 are classed as "significant" – but they believe there are more people with information and have urged them to come forward.