British boxer Amir Khan has provoked controversy in the wake of the Boston bombing after encouraging fans to "spare a thought for Syria, Pakistan, Iraq, Palestine and all the countries that are bombarded frequently".

The 26-year-old four-time world champion paid tribute to the victims of the tragedy which killed three people and injured 176.

Eight-year-old Martin Richard, from Boston, 29-year-old Krystle Campbell, from Medford, Massachusetts and 23-year-old Boston University student Lu Lingzi, from Shenyang, Liaoning were all killed by bombs which exploded near the finish line of Monday's race.

"96 countries took part in the Boston Marathon today, this was an attack on the world, not just America," Khan wrote on his official Facebook page.

"Pray for Boston tonight and whilst praying for them also spare a thought for Syria,Pakistan, Iraq, Palestine and all the countries that are bombarded frequently.

"We live in a dark world let's make it better with the light of our prayers. AK."

Khan's post, which has already been liked by 744,400 people, quickly divided the online community.

While some hailed the athlete for drawing attention to ongoing conflict around the world, others accused him of using the 'back-handed tribute' to spread his own political agenda.

"Nice one you must be proud that your keeping the anti-Muslim stereotype alive eh." one critic said.

Although no group has yet claimed responsibility for the bombings, another Facebook user claimed: "Sadly this tragic incident in Boston will trigger the media to accuse and defame Muslims which is always the case.

"Reporters and editors would start speculating "alqaiyda" is behind all this. me preaching here wouldn't change the system or prevent such incidents from happening."

One commentator insisted that its was " good America is bombed.. they should feel what happens Tu us Pakistanis all the year."

To which another user responded. ""A 8 year old baby died! You people make me sick!"

President Barack Obama said officials don't know "whether it was planned and executed by a terrorist organisation, foreign or domestic, or the act of a malevolent individual."

FBI Special Agent Richard DesLauriers told a news conference that the two bombs were fashioned from pressure cookers packed with explosives, nails and other lethal shrapnel.

No suspect has been taken into custody yet, and Boston police and firefighters have announced a $50,000 reward for information leading to arrests.

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