A global Muslim leader told followers that the Westminster terror attack was a “violation of everything Islam stands for”.
His Holiness Hazrat Mirza Masroor Ahmad, the Caliph of the worldwide Ahmadiyya Muslim Community (AMC), said that terrorist acts carried out in the name of Islam were against its true teachings.
He was speaking at the National Peace Symposium being held at the Bait-Ul-Futuh Mosque in Morden, south London.
The caliph said: "First of all, I would like to extend my deepest condolences to all those affected by Wednesday's terror attack at Westminster.
"Our thoughts and prayers are with the people of London at this tragic time.
"On behalf of the Ahmadiyya Muslim Community I wish to make it categorically clear that we condemn all such acts of terrorism and offer our heartfelt sympathies to the victims of this atrocity."
He added: "No matter what terrorists may claim, under no circumstances are indiscriminate acts, or killings ever justified."
Referring to Islamist terrorists, he continued: "Their barbaric acts are a violation of everything that Islam stands for."
The AMC is a peaceful Islamic movement that has denounced all forms of extremism and promotes peace.
It has been in the UK for more than a century, and has around 35,000 UK members.
Across the world it has tens of millions of members spread across 206 countries.
The theme for this year's conference was Global Conflicts and the Need for Justice and saw Hiroshima survivor and campaigner, Setsuko Thurlow, awarded with the international Advancement of Peace prize in recognition of her lifelong struggle for nuclear disarmament.
Prime Minister Theresa May sent her best wishes for the event.
In a message to the conference, she said: "The symposium is an annual reminder of your community's commitment to promoting peace around the world."
Mrs May added that she appreciated the work of the AMC in promoting justice and tolerance throughout society.
As well as murdered police officer Keith Palmer, Khalid Masood's victims in the attack included US tourist Kurt Cochran and his wife Melissa, from Utah, who were on the last day of a trip celebrating their 25th wedding anniversary. Mr Cochran was killed and Mrs Cochran was badly injured.
Aysha Frade, who worked in administration at independent sixth-form school DLD College London, in Westminster, also died. She is believed to be a 43 year-old married mother of two.
Leslie Rhodes, a retired window cleaner from Clapham, south London, died from injuries sustained in the attack. He was described by neighbours as a "lovely man".