Memorial service for Islamic State victim David Haines

More than 600 people have attended a memorial service for David Haines, a British aid worker who was killed by Islamist militants in Syria last month.

Mr Haines was murdered by the Islamic State (IS) group after spending more than a year as a hostage.

The service was held in Perth, where the 44-year-old grew up.

Barbara Henning, the wife of taxi driver Alan Henning, from Eccles in Greater Manchester, who was also killed by IS militants, was at the memorial.

She had travelled there with her two children.

Mrs Henning and Michael Haines stood together and held hands outside the church before going inside.

Mr Haines' family said the event would be a celebration of his life, and asked for donations to the charity Hostage UK instead of flowers.

They also asked for those attending the service at Perth Congregational Church to wear brightly-coloured clothes.

One man in the congregation wore a colourful yellow Hawaiian-style shirt and red tartan trousers.

Serving or former Armed Forces personnel attending were asked to wear their berets in recognition of Mr Haines' service in the RAF.

RAF personnel formed a guard of honour, while crowds gathered in the street as the service took place.

Mr Haines' brother Michael addressed family, friends and colleagues.

He called on people to join together and "find a single act of unity" in the wake of the barbaric killing of his brother.

Both he and David Haines' daughter Bethany shared some of their memories during the service while Michael Haines' son, Euan, read a poem, Not How Did He Die, But How Did He Live, in memory of his uncle.

The service also featured several hymns, including Amazing Grace and I Vow To Thee My Country, as well as the song Going Home, by the Scottish band Runrig.

Scottish Finance Secretary John Swinney was among those who attended, going into the church with fellow local SNP politician Pete Wishart MP.

Shortly before proceedings got under way, a group of about 20 bikers drove past, revving their engines, as part of a tribute said to have been organised by a family friend.

The minister who led the service, the Reverend Gordon Campbell, said Mr Haines was a "son of Perth" whose legacy needed to be celebrated.

Speaking after the service, he said: "He was an adventurous guy, with a sense of fun, but I think he will be remembered above all for his caring disposition and his concern for other people, and that was something we were reflecting on in the service."

He added: "It was billed as being a service of celebration and thanksgiving.

"We started off by saying that, despite what people might think, you are allowed to smile, or even laugh, in church.

"And there was laughter. There were tears as well but a lot of laughter. And sometimes tears and laughter are not as far apart as you imagine.

"We tried very much to be uplifted by David's achievements, David's life, David's legacy, but we were also trying to think how we let that legacy live on in our lives."

He said the service had a "message of peace and reconciliation", adding that the Muslim Council for Scotland had been represented in the congregation.

Both David Haines and Alan Henning were beheaded months after being kidnapped while on aid missions.

Mr Haines and Ms Henning have written a joint letter calling for "acts of unity" against IS militants.

A book of condolence has opened in Perth for David Haines, a father-of-two, who was taken hostage in Syria while working for international relief agency Acted in March last year.

Mr Haines, who was born in Holderness in Yorkshire and raised in Perth, had previously done relief work in post-war Croatia, where he eventually settled with his second wife and four-year-old daughter, as well as working in Libya and South Sudan.

Primer Minister David Cameron condemned his death as an "act of pure evil", and his 17-year-old daughter Bethany called for IS to be "eradicated".

In the letter, Michael Haines and Barbara Henning condemn "those who seek to drive us apart" and urges all religions to find "a single act" in the coming weeks that "draws people together".

They said their loved ones had been delivering "vital humanitarian support to those who needed it most".

"Their desire to help was not driven by their religion, race or politics but by their humanity. David and Alan were never more alive than when helping to alleviate the suffering of others," they said.

"They gave their lives to this cause and we are incredibly proud of them."

Mr Haines and Mrs Henning said they had been "overwhelmed" by messages of support from within the UK and around the world.

Hundreds of people attended a memorial service for Mr Henning last week, while Prime Minister David Cameron this week said he would consider recognising the murdered aid worker with a national honour.

In a separate video message, Michael Haines said he wanted other families to understand that terrorism and extremism was not "something that happened to other people", adding: "It affects us all."

"Together we have the power to defeat the most hateful acts," he said.

He said his brother was an "ordinary guy from Perth who did extraordinary things".

"My brother's killers want to hurt all of us and stop us from believing in the very things that took David in conflict zones," he said.

"My brother didn't see nationalities or religions, he just saw other human beings in need of a little help to get by - or sometimes a lot of help to live to see another day.

"This is how my family will remember him," he added.

IS has killed two other Western hostages in the past two months - US journalists James Foley and Steven Sotloff - and is holding the British journalist John Cantlie, who has appeared in a series of propaganda videos.