A pedestrian died after a man in a white van drove into worshippers near the mosque in London, at 12.20am this morning (Monday).
Qari Asim MBE, imam of Leeds Makkah Mosque, said he was now working with police about increasing security at the city's mosques following the attack, which took place as people were praying during the holy month of Ramadan.
"It's appalling that someone motivated by hatred has once again sought to kill and maim innocent people on Britain's streets," he said.
"Fascists of the far right and ISIS extremists alike both hate our society and its values.
"Through terrorism they try to tear it apart. It's important that we seek out those who incite hatred, of whatever form, to challenge and condemn their vile actions.
"There can be no tolerance of religious hatred in our country."
The van driver, described by witnesses as a large white man, was detained by members of the public until police arrived after the attack in Seven Sisters Road, London.
Mr Asim, who is also an independent member of the Government's Anti-Muslim Hatred working group, urged people to remain calm and vigilant.
He said: "Given that there has been five-fold increase in anti-Muslim hatred since the London Bridge attack, Muslims are deeply concerned and anxious about growing levels of Islamophobia.
"But we must remain calm and vigilant, and increase security around mosques. We must stand together to drown out extremism and hatred with hope, and unity."
"On one hand we need to have increased security at mosques in Leeds but at the same time we need our public spaces to be open all day.
"We are working with the police to have an increased presence to make sure people are reassured."
"Ultimately, it's a battle of ideology now. No matter how much protection we have around our mosques, we need to fight extremism."
The attack came after communities across the country took part in The Great Get Together, in honour of former Batley and Spen MP Jo Cox, who was murdered one year ago.
Mr Asim added: "Millions of people came together all over Britain this weekend, with their friends, neighbours and with complete strangers, to share all that we have in common at the Great Get Together."That showed Britain at its best - a peaceful, tolerant, welcoming society and a wonderful place to live. We must stand firm and defend that society together."