South Yorkshire's assistant chief constable David Hartley says his force won't bow to terrorists in the wake of last night's attack on London.
ACC Hartley said his force in Yorkshire was prepared to 'protect the public' in South Yorkshire.
"I want to offer my reassurance to our communities across South Yorkshire that we are prepared," ACC Hartley said.
"We have a command structure in place at all times. We have increased numbers of armed staff available, and we are planning to support all our events and crowded places.
"We are here to support you carrying on as normal.
"We will continue to serve and protect the public in South Yorkshire, as do all our colleagues across the country, to the best of our ability and maintain a high level of service and delivery.
ACC Harley offered his condolences to the victims of the attack and their families.
"Our thoughts are with everyone affected by the atrocities that took place yesterday evening and to the families and friends of those who have sadly lost their lives due to the abhorrent and truly unthinkable actions of others," he said.
"While the threat level remains at severe for the UK, indicating an attack of this nature is likely, for one to occur so soon after the attack in Manchester is understandably worrying and un-nerving for all of us."