Armed police have been deployed at Scotland's largest Christmas market as security is tightened at events across the UK.

It follows the deaths of 12 people at a festive village in Berlin last December, when a rented truck was driven into the crowd in an act of terror.

Heavy concrete barriers intended to prevent a similar attack have been installed at the Princes Street market in Edinburgh, which is expected to welcome around 900,000 visitors this year.

Armed police could also be deployed in Glasgow and Aberdeen, which are hosting their own seasonal events.

Superintendent Mark Rennie said: "We are committed to ensuring the safety of all of those who live within Edinburgh or who come to visit during the Christmas seasonal period.

"We will have an increased deployment of officers throughout the city centre as part of our festive policing campaign.

"We will be engaging with the public to offer a range of crime prevention and personal safety advice while at the same time providing a visible presence to deter crime and deal with any issues that arise."

The UK's terror threat level remains at severe - meaning an attack is highly likely - and armed officers have also been seen on patrol in London, Birmingham, Manchester, Leeds and Bath.