Qur'an burning would increase risk of terror attacks – Interpol

• 'Strong likelihood' of violent attacks if if burning goes ahead
• US pastor hints at cancelling event if contacted by Obama

Interpol, the international police agency, has warned of an increased risk of terror attacks if the planned burning of the Qur'an by extremist US pastor Terry Jones takes place on Saturday.

"If the burning goes ahead as planned there is a strong likelihood that violent attacks on innocent people would follow," Interpol, acting partly on a request from Pakistan, said in a statement.

The warning came as Jones, a pentecostal preacher from Gainseville, Florida, hinted he might be prepared to call off the burning – planned to mark the anniversary of the 9/11 attacks – if he was contacted directly by Barack Obama, the state department or the Pentagon.

"That would cause us to definitely think it over," Jones told USA Today. "That's what we're doing now. I don't think a call from them is something we would ignore." But he said that as things stood he was "not convinced that backing down is the right thing".

Barack Obama – speaking after Jones's interview with the US newspaper – joined mounting worldwide condemnation of the plan, saying the event would be a "recruitment bonanza for al-Qaida".

The US president told ABC News: "If he's listening, I hope he understands that what he's proposing to do is completely contrary to our values as Americans," Obama said.

Obama said the event was a stunt that would boost support for terrorism. "This could increase the recruitment of individuals who would be willing to blow themselves up in American cities or European cities," Obama said.

The president repeated a warning by General David Petraeus, the commander of US and Nato forces in Afghanistan, that the burning would endanger US troops.

"And as a very practical matter I just want him [Jones] to understand that this stunt could greatly endanger our young men and women who are in uniform," Obama said.

David Cameron's spokesman said earlier that the prime minister strongly opposed any attempt to offend members of a religious group.

Religious leaders of all faiths have warned against the event, with statements of protest coming from both the Vatican and the Archbishop of Canterbury.

This week protests took place in the Afghanistan capital of Kabul where effigies of Jones were burned alongside the American flag.

Anjem Choudary, the former leader of the banned Islamist organisation Islam4UK, told Reuters he was calling on radical Muslim groups around the world to burn American flags outside US embassies in retaliation.

Today about 200 lawyers and civilians marched and burned a US flag in the central Pakistani city of Multan, demanding that Washington prevent the book burning.

The foreign ministries of Pakistan and Bahrain issued some of the first official denunciations in the Muslim world, with the latter calling it a "shameful act which is incompatible with the principles of tolerance and co-existence".

The president of Indonesia, the world's most populous Muslim nation, has written to Obama asking him to stop the bonfire. Susilo Bambang Yudhoyono told Obama that images of the Qur'an in flames could "threaten world peace", according to his special adviser Heru Lelono.

India's home office has asked its country's media to exercise restraint in reporting on the planned burning.

The rightwing US presidential hopeful Sarah Palin urged Jones and his supporters to reconsider. Writing on her Facebook page she said: "People have a constitutional right to burn a Qur'an if they want to but doing so is insensitive and an unnecessary provocation – much like building a mosque at Ground Zero."

In a statement on his faith foundation website, Britain's former prime minister Tony Blair, said: "Rather than burn the Qur'an I would encourage people to read it".