Wimbledon fans have been warned to avoid touts if they want to buy any last-minute tickets for the Championships - or else run the risk of being scammed.

With the tournament well under way, those wanting a glimpse of Andy Murray or Serena Williams in the flesh are being urged to only buy tickets from authorised sellers.

Fans arriving at SW19 can also expect to see armed police officers wandering the grounds of the All England Club in response to the heightened threat of global terrorism.

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The current threat level for international terrorism in the UK is severe, and the Metropolitan Police has made a conscious decision this year to make armed officers more visible, offering a reassuring presence to spectators.

Temporary Commander Nick Downing said: "We have deployed armed officers before but we are going to make them far more visible.

"We are constantly reviewing our policing plan for Wimbledon and we are always aware of events going on around the world, the tragic events in Paris and Orlando.

"There have been tragic events across the world, we don't want to be complacent, we need to respond appropriately but proportionately, and by just changing how our officers are patrolling is just cognisant of that threat."

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Armed officers will carry out patrols similar to those seen at the London Olympics in 2012, or more recently at Wembley following the Paris attacks in November, Mr Downing said, adding: "It's important that the public feel safe."

With 39,000 people in the ground at any one time, Mr Downing advised fans to take care of their belongings.

He urged them to avoid ticket touts, warning extra police would be patrolling nearby tube and train stations, as well as the Wimbledon queue.

He said: "You don't know what they are selling you - is it fake tickets, is it genuine tickets. There are places where you can get your tickets which will be through the authorised sellers online, or by going to the tennis club itself.

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"Don't entertain touts. You don't know what you're buying - don't take that risk.

"By taking those simple steps you will have a fantastic championships and hopefully we will see a British winner."