LONDON — Police said Sunday that a seventh person has died in a rampage at two of the British capital's most iconic attractions that also left dozens injured. It was the third terror attack in Britain in less than three months.

Police said a van plowed into pedestrians on London Bridge and that assailants went on a stabbing rampage at nearby Borough Market late Saturday. Forty-eight people were also injured. Police, who said they are treating the attack as a terrorist incident, fatally shot three suspects. The victims are being treated at five hospitals across London.

Metropolitan Police Commisioner Cressida Dick said she did not believe any more attackers were at large. She refused to comment on the identity of the assailants.

In one photo, police stand over what appears to be two of the suspects. One of the suspects is wearing what appears to be a suicide vest, which police later said was fake.

Mark Rowley, head of counter-terrorism for Metropolitan Police, said all the attackers are thought to be dead, but investigators are working to determine if any potential accomplices remain at large.

Holly Jones, a BBC reporter who was on the bridge when the attack happened, said she saw a van travelling at about 50 miles an hour.

"He swerved right round me and then hit about five or six people. He hit about two people in front of me and then three behind," she told the BBC.

Prime Minister Theresa May called for tougher measures to contain Islamic extremism in a statement outside her offices in Downing Street on Sunday.

She said the recent attacks are not directly linked, but “terrorism breeds terrorism.”

“They are bound together by the single evil ideology of Islamist extremism that preaches hatred, sows division, and promotes sectarianism,” she said. “It is an ideology that claims our Western values and freedom, democracy and human rights are incompatible with the religion of Islam."

"It is time to say enough is enough" May said.

London Mayor Sadiq Khan said: "There are no words to describe the grief and anger that our city is feeling this morning," in a statement Sunday.

"I am appalled and furious that these twisted and cowardly terrorists deliberately targeted innocent Londoners and visitors to our city who were just enjoying their Saturday night," he added.

He urged all Londoners to "remain calm and vigilant today and over the days ahead."

PHOTOS: London bridge terror attack

Khan said some of the victims were critically injured. A British Transport Police officer, one of the first on the scene, was injured on the head, face and leg as he responded to calls for help from the public. His injuries are serious but are not thought to be life threatening, authorities said.

French President Emmanuel Macron says French nationals were among the injured. He denounced the “abominable and cowardly” attack and said France will continue fighting “terrorism with all our strength alongside Britain and all other countries concerned.”

No group has claimed responsibility for the attack. Eyewitnesses said they heard the men shout "this is for Allah,” British media reported.

President Trump tweeted: "Whatever the United States can do to help out in London and the U. K., we will be there - WE ARE WITH YOU. GOD BLESS!"

Britain has weathered two other terror attacks in recent months. On March 22, five people were killed in London after Khalid Masood rammed his car into pedestrians on Westminster Bridge before fatally stabbing a policeman outside the Houses of Parliament. Masood was shot dead by police. The Islamic State said a "soldier" from the group carried out the attack. Police later said Masood had no links to extremist groups such as ISIS or al-Qaeda.

On May 22, Salman Abedi, a British-born suicide bomber, killed 22 people and injured 59 others at an Ariana Grande concert in Manchester, northwestern England. Abedi died at the scene. ISIS claimed responsibility but that claim cannot be verified.

The attack Saturday came on the eve of a benefit concert by Grande for victims of last month's Manchester Arena bombing in aid of the victims and their families. Police said the event would still take place, with additional security in place.

"We're deeply saddened to hear about last night's horrific attacks in London and our thoughts are with everyone affected," said Greater Manchester Police's Assistant Chief Constable Garry Shewan.

The ruling Conservative Party and the opposition Labour Party suspended election campaigning Sunday. it will resume on Monday.