Ariana Grande has been among the stars leading tributes to the victims of the London terror attack that claimed at least seven lives on Saturday night.

The American pop star took to Twitter to express compassion to those suffering after a trio of alleged terrorists ploughed into members of the public on London Bridge and went on a stabbing spree before being shot dead by police.

Ari took to Twitter shortly after news of the attack broke, saying “Praying for London” alongside a heart emoji.

Other stars took to social media to express shock, dismay, grief, and unity following the attack that also injured 48 people.

Former Geordie Shore star Charlotte Crosby claimed to be in London at the time of the attacks, writing on Twitter: “Praying for every1… can here the police cars and ambulances.”

Simon Cowell was among stars tweeting tributes, writing: “Thoughts are with innocent victims caught up in London Bridge incidence. Please try to stay safe people.”

The attack comes less than two weeks after 22 people were murdered by a suicide bomber outside Ariana Grande’s concert in Manchester Arena.

The star visited victims in hospital this week – including eight-year-old Lily Harrison who was hospitalised after being hit by shrapnel following the attack.

Ariana told her: “I’m so proud of you. You are so strong. You are doing really well.”

Lily’s father - 32-year-old Adam - said: “Ariana lit the room up. She was absolutely fantastic. She knelt by Lily’s bed and asked her lots of questions. She had so much time for her.”

A tribute concert organized by Ariana for the victims of the Manchester bombing will go ahead tonight.

'MTV stands strong with all of you in the fight against global terrorism. Recent attacks in Manchester UK, Kabul Afghanistan, Minya Egypt, Baghdad Iraq and London UK are remindersof the countless people who have lost their lives in terrorist acts, but the One Love benefitconcert is a reminder to us all that we're always stronger together.'

WATCH: Ariana Grande pay tribute to victims of Manchester Arena bombing