Several Middle East governments hail bin Laden's demise but Hamas condemns the killing of a "Muslim and Arab holy warrior".
Mixed response from Middle East
Osama bin Laden's death drew a mixed response in the Middle East where he was already seen as a spent force made irrelevant by the Arab Spring.
The pro-democracy uprisings sweeping the region are a determined rejection of his ideology of violence, which only appealed to a tiny minority, commentators said.
"Al Qa'eda was in eclipse. To be specific it was buried in January 2011 in Tahrir Square," said Jamal Khashoggi, a prominent Saudi journalist. The real story, he said, was that bin Laden had evaded capture for so long.
"It was a big failure of US intelligence," he told Arab News, an English-language Saudi daily.
Several governments in the region, including those of Saudi Arabia, Iraq, Turkey, Yemen, Israel and the Palestinian Authority, hailed bin Laden's demise. Hamas, however, condemned the killing of a "Muslim and Arab holy warrior", while insisting it had no ties with al Qa'eda.
Egypt's Muslim Brotherhood - scorned by al Qa'eda for its moderate approach - also branded bin Laden's killing "an assassination", saying it favoured "fair trials". It joined Iran in insisting that the al Qa'eda leader's death removed "any excuse" for the US and its allies to keep forces in the Middle East under the pretext of fighting terrorism.
But Libya's rebels said it would be a great "gift" if the US now killed the Libyan dictator, Muammar Qaddafi.
Jordan's Muslim Brotherhood said it did not endorse al Qa'eda's tactics but predicted another leader could emerge unless the international community changed its attitude toward Islam, the Palestinian issue and corruption in the Middle East.
Jihadist forums were disconsolate.
"Oh God, please make this news not true. God curse you Obama," said one message on an Arabic internet chat site. "Oh Americans, it is still legal for us to cut your necks." An internet outlet for official messages from al Qa'eda pledged that its "holy war" would continue.
In Saudi Arabia, where bin Laden was born but stripped of his citizenship in 1994, an official statement said the Saudi people had in particular been targeted by "this terrorist organisation". Riyadh hoped his death would boost international "efforts against terrorism".
Bin Laden was a sworn enemy of the US-backed Saudi monarchy. Popular sympathy for al Qa'eda in the kingdom largely evaporated after a series of indiscriminate terrorist attacks between 2003 and 2006 that killed many Muslims as well as Westerners.
Journalists in Riyadh said Saudis also wanted to forget about bin Laden because he had tarnished Islam.
"Bin Laden has been off the radar for a long time. I was eavesdropping on conversations in Starbucks this morning and his name was hardly mentioned.
"Two men were talking about German football instead," a longtime Saudi journalist said in a telephone interview.
Lebanon's outgoing premier, Saad Hariri, said the al Qa'eda leader's tactics had backfired.
"The damage he (bin Laden) has done to Islam's image and Arab causes is not less than the damage done by enemies of Muslims and Arabs worldwide," Mr Hariri said.
Iran demanded the withdrawal of US soldiers from Afghanistan and Iraq.
The foreign ministry spokesman, Rahim Mehmanparast, said: "The US and their allies have no more excuse to deploy forces in the Middle East under the pretext of fighting terrorism."
Tehran has long viewed al Qa'eda as a threat, fearing its extremist brand of Sunni radicalism, which is hostile to the Shiite faith. In 1998, Iran was on the brink of war with Afghanistan, then controlled by the Taliban, which was sheltering al Qa'eda.
Many of bin Laden's closest relatives have been under house arrest in Tehran since fleeing Afghanistan after the September 11 attacks on the US.
Israel's prime minister, Benjamin Netanyahu, congratulated President Obama for bin Laden's "elimination".
It was a "victory for justice, liberty and the common values of democratic nations which fought side by side against terrorism". The Western-backed Palestinian Authority said bin Laden's death was good for the cause of peace".
Turkey's president, Abdullah Gul, welcomed bin Laden's death "with great satisfaction" and said the "way in which he was eliminated should serve as an example to everyone".
Twin al Qa'eda attacks in Turkey eight years ago killed 63 people, including the British consul.
The 57-member Organisation of the Islamic Conference stressed that terrorism was against the teachings of Islam.
It released a statement saying: "The OIC believes that the activities against terrorism should address the real causes of terrorism rather than dealing with its external manifestations."
* With additional reporting by Hugh Naylor in Jerusalem, Suha Philip Ma'ayeh in Amman and Zoi Constantine in Beirut