People should "brace themselves" for further terror attacks during Islam's holy month of Ramadan, a security expert has warned in the wake of the London Bridge attack.

Dr Sajjan Gohel said the latest atrocity was strikingly similar to the modus operandi used in March's attack in Westminster.

The international security director at the Asia-Pacific think tank added that the quick succession of attacks was "designed to wear us down".

Citizens should "brace ourselves" for more attacks to come, he told London's Evening Standard newspaper.

“The sad thing is that this attack is not surprising. We’ve seen this tactic, called ‘the just terror’. We saw it in Westminster and now we’re seeing it again," he said.

“It’s designed to wear us down. It’s psychological - it’s visual, graphic, and it’s relentless."

It comes as security services reportedly expressed "deep concern" over extremists emulating previous acts of terror.

Authorities face increasing difficulties uncovering plots by small groups who may not have links with established jihadi networks and thus may have escaped scrutiny.

The attackers used knives and a hired van in the London attack, echoing Westminster attacker Khalid Masood who killed five people using knives and a hired car.

Anas Amri also killed 12 people in Berlin using a hired truck, while Mohamed Lahouaiej-Bouhlel who killed 86 in Nice using another rented lorry.

Police have reportedly identified all three attackers who perpetrated the violence on London Bridge and nearby Borough Market, but their names have not yet been made public. All three were shot dead at the scene by armed police.

It came less than two weeks after the Manchester bombing and months after March's Westminster attack.