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World leaders have voiced outrage at the assassination of Pakistan's opposition leader Benazir Bhutto and expressed fears for the fate of the nuclear-armed state.
US President George W. Bush condemned the killing as a "cowardly act" and urged Pakistanis to go ahead with a planned election. Russian President Vladimir Putin called it "a barbaric act of terrorism" that was a challenge to the world.
British Prime Minister Gordon Brown said Bhutto had risked everything to try and bring democracy to her country, of which Britain used to be the colonial ruler.
"The terrorists must not be allowed to kill democracy in Pakistan," he said.
Bhutto was killed in a gun and bomb attack as she left a rally ahead of an election due on Jan 8. The identity of the attacker was not immediately clear, but Islamist militants have been blamed for a previous assassination bid.
"The subcontinent has lost an outstanding leader who worked for democracy and reconciliation in her country," said Prime Minister Manmohan Singh of India, Pakistan's giant neighbour and nuclear rival.
"The manner of her going is a reminder of the common dangers that our region faces from cowardly acts of terrorism and of the need to eradicate this dangerous threat."
French President Nicolas Sarkozy called the killing odious.
"France, like the European Union, is particularly attached to stability and democracy in Pakistan," he said in a letter to Pakistan's President Pervez Musharraf.
Pakistan was already a big global worry.
The US ally has been struggling to contain Islamist violence while Musharraf, whose popularity has slumped, only lifted a state of emergency on Dec 15 after six weeks.
Bush urged Pakistanis to honour Bhutto's memory by continuing with the democratic process and said those behind the attack must be brought to justice.
"The United States strongly condemns this cowardly act by murderous extremists who are trying to undermine Pakistan's democracy," he told reporters at his Texas ranch.
UN Secretary-General Ban Ki-moon said the assassination was a "heinous crime" and an "assault on stability" in Pakistan.
Jose Manuel Barroso, president of the European Union's executive arm, the European Commission, said it was "an attack against democracy and against Pakistan".
Police said a suicide bomber fired shots at Bhutto, 54, as she left the rally in a park in the city of Rawalpindi before blowing himself up. Police said 16 people died in the blast.
Commonwealth Secretary-General Don McKinnon, a New Zealander, said the killing of Bhutto was a dark day for Pakistan and for the Commonwealth.
"This is a heinous and cowardly act of violence, and an utterly senseless tragedy," he said.
"I strongly condemn this outrageous act. Violence can serve no useful purpose in any society, especially in one that is seeking to rebuild democracy and reconcile deep divisions," he said.
He said Bhutto was a woman of charisma and courage.
"I hope this terrible tragedy will make crystal clear the folly of violence and the importance of restraint and reconciliation as the only way of consolidating the democratic process. The Commonwealth stands by Pakistan in that effort," he said.
Pakistan Association of Wellington President Asjid Munier said the assassination was "tragic news".
He said he was very sad to hear that Bhutto had died and it should not have happened.
Mr Munier said the association would be praying for her, "that is all we can do", he said.
Saudi King Abdullah said the attackers were "wicked murderers who are distant from Islam and morals."
Iran's foreign ministry condemned the attack and urged calm and stability in Pakistan.
A Vatican spokesman said Pope Benedict had been informed, adding:
"It is difficult to see any glimmer of hope, peace, reconciliation in this country."
- REUTERS