ACT OF TERRORISM

Prime Minister Theresa May, who had been campaigning in the general election, returned to Downing Street to be briefed by security officials after the attack.

She said the attack in London "is being treated as a potential act of terrorism."

It is the third attack in Britain so far this year. On March 22, 52-year-old Briton Khalid Masood drove a car into pedestrians on Westminster Bridge, injuring dozens of people. He then stabbed a police officer before he was shot dead at the scene. On May 22, Briton Salman Abede blew himself up at the Manchester Arena following a concert.

Professor Anthony Glees, director of the Center for Security and Intelligence Studies at the University of Buckingham, said one of the reasons behind the attacks is that Britain has looked vulnerable at the moment, "since the Brexit vote."

"In just a short period time we have seen the attack on Westminster and Manchester... It is the weak and vulnerable that are the first to be attacked in the jungle," he told Xinhua in an interview after the Manchester attack.

"We had the referendum, a change of government, the premature calling of a general election and in the days preceding the Manchester bombing we had a prime minister who had to change her party manifesto. We looked as if we were all over the place and that made us vulnerable," he said.

Dr. Imran Awan, associate professor of Birmingham City University, said Britain has long been a target of terrorist groups along with other European countries.

"But Britain and the United States as superpowers would be viewed as prized Number One targets, high up on the lists of ISIS and other terror groups," he told Xinhua.

Political analysts fear the attack would cast shadows on the upcoming general election. However, it is still unclear to what extent it will affect voters.

A British girl wrote on her social media account that she does not care about which party could win the election nor their manifesto, "I just wish there is no more terror attacks."