The white van plowing into pedestrians on the London Bridge and the stabbings at Borough Market on Saturday evening resulted in the deaths of six civilians, along with three male suspects involved in the terror attacks, BBC reports.
Mr. Trump began tweeting about the incidents an hour or so after initial news reports.
Police tweeted a warning telling people in the area to run to safety, hide and then call police if it is safe to do so.
An armed Police officer looks through his weapon on London Bridge. Two attacks, at Borough Market and London Bridge were being treated as terror incidents.More news: Attacks In London Leave Unknown Number Dead & Injured
This story is developing and we will provide additional information as it becomes available. A man reportedly entered the eatery and stabbed at least two people. "He hit about two people in front of me and then three behind", Holly Jones told the British TV network.
The force initially said officers were also responding to a reported third incident, in the Vauxhall area of London.
Authorities say at least three suspects have been killed by police.
Another man, was also reported to be an attacker, was pictured on the ground a short distance away. The police have cordoned off the area and ambulances have been brought in.
Police said they were "reviewing and planning to strengthen our policing stance across London over the forthcoming days".
Another eyewitness tells Sky he heard a burst of gunfire during the incident.
We are dealing with an incident on #LondonBridge, when we have more information we will update this twitter feed. During that event, Khalid Masood killed four people and injured dozens more while driving into a crowd of pedestrians.
London Ambulance Service say they have deployed "multiple resources" to the scene.