Manchester attack: Hay Festival to increase security
The Hay Festival will step up security following the Manchester attack as the 10-day event opens on Thursday.
This year's 30th anniversary festival has 800 events and includes appearances by Stephen Fry, Graham Norton and American politician Bernie Sanders.
But organisers have warned visitors they will face extra security.
Director Peter Florence said the the world-famous festival had undergone a "comprehensive review" of its security, together with Dyfed-Powys Police, in the wake of the Manchester attacks that killed 22 people.
"We have put in some measures that will make sure that the values and the joy that we celebrate in Hay can go ahead," Mr Florence told BBC Radio Wales' Good Morning Wales programme.
"It is very important for all of our visitors to know that they will be safe and that what they want to talk about freely and openly, which is what the people who attack Britain and the west most despise, is able to go ahead in the way that we want it to."
Festival organisers have asked visitors to allow extra time for arrival at the festival site and not take large bags or rucksacks.
The festival began in 1987 but has grown to become one of the world's leading events for writers and their fans.
As well as authors discussing their work, it includes celebrity guests, comedians and live music.
Among the entertainment will be performances by Will Young and Amy MacDonald.
Former American president Bill Clinton appeared at the festival in 2001 and described it as the "Woodstock of the mind".
Another former US president Jimmy Carter appeared at the event a few years later, while the festival has hosted writers and poets including Arthur Miller, Maya Angelou, and Seamus Heaney.
In recent years Sir Tom Jones, Benedict Cumberbatch and Dame Judi Dench have all appeared at Hay.
The festival opens with two days of events for schools, with talks streamed into classrooms for those who won't make it to Hay-on-Wye. Events typically last an hour, with audiences filling temporary marquees on a field a mile south of the town.