Italian authorities warned the United Kingdom about a designated terrorist. On Tuesday, British police went out with the name of the third person they believed was involved in the terrorist attack in London. The man's name is Youssef Zaghba, a 22-year-old from East London.

Surveilled in Italy

According to Giuseppe Amato, Attorney General in Bologna, who investigated Zaghba when attempting to travel from Italy to Syria to join IS in March 2016, Italian authorities warned Britain about Zaghba.

Amato says that he personally saw a report that had been sent to London by the head of the counter-terrorism unit in Bologna regarding Zaghba.

"We did our best. We could only monitor him and send a note to the British authorities. That's all we could do and we did. Since moving to London, he was in Italy once more for a total of 10 days. And during the ten days he was never out of sight for us," said Amato, emphasizing that they "watched every step" Zaghba took in Italy. The British intelligence service should do look upon Zaghba as significant enough to note him down on the police list of particularly suspicious people.

Radicalized in England

Zaghba moved to London from Italy a year ago. According to the 22-year-old's mother, he must have been radicalized in England. Prior to moving to England, he had wanted to go to Syria to establish a family in a religious climate, not to practice war.

Zaghba's short time in England

"Last year, when he returned from England, he was a bit more rigid. I could look at his face and his expression that he had been radicalized. And it happened in England, said his mother, Khadija Collina, according to the news agency AP. She also confirms that Italian intelligence kept an eye on him when he was in Italy.

She warned him that he had to behave since he had come to the police spotlight. "Now you must perform perfectly and as a gentleman. You should not even look at something suspicious on the internet, you should meet the right people and do the right things," Collina told her son.

Known by the British intelligence

On Monday, the police released the names of the other two men who participated in the terrorist attack -- 27-year-old Khuram Butt and 30-year-old Rachid Radouane.

Khuram Butt was known to British intelligence, even though they had no evidence that he should have planned any attack.

He appeared in the documentary "The Jihadist Next Door", which was broadcast on Channel 4. The documentary is about the rise of extreme Islamism in London. Butt must have been radicalized in 2013 when he started going to a conservative mosque in East London. Butt would also have been a supporter of the Forbidden Islamist group al-Muhajiroun, who last month tried to persuade people in London not to take part in the British election, The Guardian writes.

The pressure is increasing on British police

The pressure is now increasing on British police because people are asking themselves if the police could have done more in order to stop the three terrorists.

"It is not unreasonable that these questions are asked. I am sure the police will look into what they knew, what they could have done, what they actually did and if anything could have been done differently," London's mayor, Sadiq Khan, said to the BBC.

Prime Minister Theresa May has said that she will change British human rights laws if it is necessary to deal with people who may constitute a terrorist threat. Eight people were killed when the three men ran a truck into pedestrians on the London Bridge before they knocked out casual victims.