South Wales Police are working with their counterparts in the Met to investigate the Finsbury Park attack after it emerged the van driven at pedestrians was hired in the village of Pontyclun.
The Secretary of State for Wales, Alun Cairns, said he had spoken to the Chief Constable of South Wales Police, Peter Vaughan.
“He has assured me that his team is fully engaged and working in partnership with the London Metropolitan Police as the investigation into the abhorrent attack at Finsbury Park gets under way,” Mr Cairns said.
Pictures of the van indicated it was rented from Pontyclun Van Hire, northwest of Cardiff.
Staff at the firm said they were “shocked and saddened” by what happened.
In a statement, they said: “We are co-operating fully with the Metropolitan Police investigation and our thoughts are with those who have been injured in this cowardly attack.
“We will not be making any further statement because of the ongoing police investigation but will continue to assist the police in any way we can.”
Police officers were at the firm on Monday.
Hannah Jenkins, 23, who works in the local Spar shop, said: “I think everyone is in shock. This is a small village in Wales and you don’t expect something like this here.”
Another retail worker, Helen Edwards, said: “It was a shock to see the van was from Pontyclun.
“When it’s so close to home it’s even scarier.”