Image copyright Reuters Image caption Sheik Qais al-Khazali said the kidnaps and killing should not have happened

The head of a Shia group that kidnapped five Britons in Iraq in 2007 - and killed four of them - has apologised.

IT expert Peter Moore, from Lincoln, was freed in December 2009, but his captors killed his four bodyguards.

Sheik Qais al-Khazali, leader of Asaib Ahl al-Haq - or League of the Righteous - blamed the UK for the deaths, saying it "was not serious" in negotiations.

The government said responsibility for the deaths lay "entirely with those who kidnapped and murdered them".

A Foreign Office spokesperson added that "all kidnaps of British nationals are taken extremely seriously".

Alec MacLachlan, from Llanelli, South Wales, Jason Swindlehurst, from Skelmersdale, Lancashire, Jason Creswell, originally from Glasgow, and Alan McMenemy, from Glasgow, were acting as bodyguards for Mr Moore when they were all taken hostage.

The captors had wanted to use the men as part of a hostage exchange.

Second-class citizens

I think that the British government is responsible for their deaths because it was not serious in the negotiations with the side that held them Sheik Qais al-Khazali

League of the Righteous is now a political force - as well as a military force - in Iraq.

In an interview in Baghdad, Sheik Qais al-Khazali told the BBC's Middle East editor Jeremy Bowen he had been in prison when Mr Moore and his team were taken.

He said he was sorry for the deaths, adding that the kidnaps and the killings should never have happened.

"I think that the British government is responsible for their deaths because it was not serious in the negotiations with the side that held them.

"If they were fast enough that wouldn't have happened.

"The British government concentrated only on Peter Moore.

"The bodyguards were second-class citizens.

"That was a surprise for us."

Image copyright Getty Images Image caption Peter Moore arrived back in the UK on 1 January 2010

Mr Moore was eventually released in December 2009 in an apparent exchange for prisoners including the Sheikh.

The League of the Righteous, which now encompasses a political party, is a powerful and feared Shia Muslim fighting group that is heavily involved in the war against the Islamic State in Iraq and the Levant (Isis).

The group emerged during the fight against the Americans and the British after the invasion of Iraq in 2003.