Armed officers who shot the London Bridge terrorists believed explosives were about to be detonated and lives were at risk, an inquest heard.

A Metropolitan Police officer, known only as BY28, told the Old Bailey he feared for his life as he made his way to the scene on June 3 2017.

The officer said his main objective was to "protect the innocent parties" and get there as quickly as possible.

BY28 told the inquest that as his vehicle arrived he spotted a man who "looked like he'd been painted in blood".

In the space of 10 minutes, Khuram Butt, 27, and Rachid Redouane, 30, from Barking and Youssef Zaghba, 22, from Ilford, had ploughed into pedestrians on London Bridge and run amok around Borough Market with knives and fake suicide belts.

All three were shot dead in Stoney Street, bringing to an end a rampage which left eight people dead and 48 seriously injured.

BY28 said as the vehicle he was in turned into Stoney Street he heard gun shots and "the whooshing sound" of bullets.

He said he saw what he believed to be armed police officers standing over suspects on the floor.

BY28 said he believed he saw improvised explosive devices (IEDs) attached to the suspects, describing them as six to eight packages on the chest with wires and cords.

The officer told the inquest that another officer also noticed what they believed were IEDs and they started to withdraw immediately.

"If they detonated they would have killed everyone there including us and members of the public," BY28 said.

The officer said he would ideally liked to have been 100 metres away from the suspects but said they needed to stay for the safety of civilians.

BY28 said he stood next to a vehicle which provided them with some protection, adding: "From an IED I knew I was in the blast radius. It was all we had."

He told the inquest that if they had withdrawn any further they would have "endangered many lives".

BY28 told the inquest: "It was protecting the members of the public and keeping the subjects contained was what we had to do and was part of our job."

The officer said he fired two shots at one of the suspects, Redouane, because he believed he was attempting to detonate the IEDs.

"He continued to move so I've taken a third shot aimed at his head," BY28 said, adding that Redouane was still trying to tug or get hold of the cord.

An officer, known only as AY14, told the inquest about the moment he was told Operation Plato - an operation declared when there is a marauding terrorist attack under way - was declared.

"It's one of those words you hear on the radio that you never expect to hear.

"I've trained for it but never actually expect to hear it," he said.

AY14 said he noticed silver packages and a brown belt with wires strapped to the suspects.

He recalled shouting at Butt: "Stay down! don't move! Stay still!"

The officer said he opened fire after Butt appeared to push himself up, adding: "I thought he was raising himself up to activate his device."

AY14 said he aimed two shots at his torso, before aiming at his head.

An officer, known only as E122, said of the terrorists: "I thought they were going to detonate and I feared for my life."

He said he shouted out: "Show me your hands. We're armed police."

E122 described how Butt started to sit up and he believed "at any second he was going to detonate his device", adding: "I feared for my life:"

E122 said he fired three shots, adding: "I thought his IEDs would detonate and I thought there would be loss of life."

Another officer, known only as AY37, recalls shouting "at the top of my voice": "IED! IED! IED!"

He said there was "absolutely no doubt at all" in his mind that the devices were viable.

The inquest continues.