Police were on high alert last night after foiling ‘active’ bomb and knife plots in the space of just five hours.

Officers shot an unarmed woman in a raid on a suspected North London terrorist cell believed to be plotting an ‘imminent’ bomb attack. Hours earlier, they arrested a knifeman said to be on the verge of carrying out an atrocity in Whitehall, just yards from Downing Street.

Yesterday it emerged that a 21-year-old teacher suspected of being at the centre of the alleged bomb plot was investigated by police in 2015 when he was said to have travelled with two other teenagers to join Islamic State fighters in Syria.

Front row seat: Mohamed Amoudi, circled, listens to controversial cleric Haitham al-Haddad at Queen Mary University of London

Mohamed Amoudi was stopped with the sixth-formers at Istanbul airport after their parents tipped off detectives. But police later released Amoudi – who has been linked to the controversial human rights group Cage – without charge.

Met Police Deputy Assistant Commissioner Neil Basu said last night: ‘Our increased activity to combat terrorism over the last two years continues – both by police and security services. Activity continues around the clock to identify and stop these threats and we are making arrests on a near daily basis.’

Hours after police held the terror suspect strolling along Whitehall carrying a backpack of knives on Thursday afternoon, officers moved to smash the alleged terror cell in Willesden, north-west London.

A group of elite officers wielding gas masks, high-powered rifles and shotguns burst into a house in Willesden Green at 7pm, smashing through the front door and flooding a flat with CS gas.

Mohamed Amoudi has been linked to the controversial human rights group Cage

At least six shots were fired, injuring a 20-year-old woman. Police said the armed operation was necessary ‘due to the nature of the intelligence that we were dealing with’.

A total of six people were arrested in connection with the raid, including five at or near the address in North London and one in Kent.

Last night it emerged that one of those was Amoudi, whose activity on social media expressing radical religious views had previously been investigated by police. Born in Yemen, Amoudi studied at Capital City Academy and was an active member of the university’s Islamic society.

Under the name Abu Umar Al-Hadrami, his Twitter feed, which has now been removed, included derogatory references to non-Muslims as ‘kuffar’ (unbelievers).

Shortly before he travelled to Turkey, Amoudi attended a talk by controversial cleric Haitham al-Haddad, who has been criticised for making homophobic remarks and supporting the death penalty for people who convert away from Islam. Amoudi was pictured in the front row of the event, organised by the Cage, listening to the cleric as he said: ‘When the leaders of kuffar are happy with your religion, then know that you’ve deviated from the right path.’

Amoudi, who described himself as a teacher on an internet profile, was a regular worshipper at a small mosque on Willesden High Road.

Officers shot an unarmed woman in a raid on a suspected North London terrorist cell believed to be plotting an ‘imminent’ bomb attack

Yesterday the imam of the Daryl Taclim Cultural Centre said: ‘He had been coming to the mosque since he came back from Turkey. I know there was trouble in Turkey but I don’t know the details. He was quiet, did not cause any trouble. He was a student so he did not come to prayers every day. Sometimes he came with his brother.’

The father of a close friend of Amoudi added: ‘I didn’t see anything like that in Amoudi.

‘I saw him six months ago. He said he wanted to be a university lecturer. This is a very, very good student. He hoped to be a university lecturer. He did physics.’ Caroline Franklin, Amoudi’s neighbour, said: ‘He seems like a lovely man. He has previously asked to do my gardening. He comes round and says: “Are there any odd jobs I can do?” He always says hello and pets my dog.

‘He lives with a woman who wears a niqab, I assume it’s his wife or girlfriend as she looks about 20 years old.’

Last night officers held a 47-year-old woman in a third unrelated terror investigation. She was held at an address in East London on suspicion of conspiring with others to fund and support terrorism.