Al-Qaida's affiliate, the Islamic State of Iraq, has named leaders to replace veterans killed by U.S. and Iraqi forces in April and has intensified its onslaught as Iraq's political barons duel for power after inconclusive March elections.

The April 18 slaying of ISI's ideological emir Abu Omar al-Baghdadi, and the Egyptian leader of al Qaida in Iraq, Abu Hamza al-Muhajr, aka Abu Ayyub al-Masri, triggered a ferocious upsurge of bombings and other attacks across Iraq, the worst violence in many months.

The attacks by the Sunni insurgents, many of them directed at the rival Shiite majority, appeared to be a bid to touch off new sectarian fighting at a time when the U.S. military is steadily reducing its strength in Iraq under a withdrawal plan slated to completed next year.

The first sign that ISI had replaced its leadership came on Friday, when the group's new "war minister," identified as al-Nasser Lideen Allah Abu Suleiman, warned in a statement of "a long gloomy night and dark days colored in blood."

The statement, posed on jihadist Web sites, vowed to avenge al-Baghdadi and al-Masri, who had served as al-Qaida's military commander.

Then on Sunday, ISI announced the appointment of Abu Bakr al-Baghdad al-Husseini al-Qurashi as ISI's caliph, or leader, and Abu Abdullah al-Husseini al-Qurashi as his deputy. Both names are undoubtedly noms de guerre.

U.S. and Iraqi officials hailed the deaths of al-Baghdadi and al-Masri as a major victory for government forces and a crippling blow for the jihadists.

But the insurgents have repeatedly shown themselves to be resilient. When al-Qaida in Iraq lost its founding leader, the Jordanian Abu Musab al-Zarqawi, in a U.S. airstrike on June 7, 2006, its attacks did not stop.

The wave of attacks the insurgents have carried out across the country in recent weeks, killing or wounding hundreds of people, underlined their ability to overcome the loss of Zarqawi's successors.

However, their political agenda may be foundering.

The Jamestown Foundation, a Washington think tank that monitors global terrorism noted in a May 7 analysis: "Al-Qaida in Iraq might remain a security threat for some time … but its project of establishing a radical state in the Sunni part of Iraq is struggling.

"Iraqi Sunnis turned out in significant numbers to vote in the recent elections, and their integration into the political system will make it even harder for the Salafi-Jihadi ideology to spread in Iraq."

The demise of such experienced warlords as al-Baghdadi and al-Masri reflected a series of setback for al-Qaida groups in the Middle East, Southeast Asia and the Afghanistan-Pakistan theater of operations.

On Sunday, the Guardian newspaper of London reported that a senior leader of al-Qaida in the Arabian Peninsula, which is based in Yemen, had been killed in neighboring Saudi Arabia, a key AQAP target.

It said Nayif Mohammed Saeed al-Qahtani allegedly organized an abortive attempt to assassinate Prince Mohammed bin Nayef, the commander of Saudi Arabia's counter-terrorism forces, in Jeddah in August 2009.

Qahtani, 24, was reportedly killed in a gunfight with Saudi security forces in April. The Guardian reported that a member of AQAP's leadership had confirmed Wahtani's death.

In Indonesia, the world's most populous Muslim nation, the elite national police counter-terrorism unit, Detachment 88, shot dead Dalmutin, a key jihadist leader, in a raid in Central Java on March 9.

The Afghan-trained Dulmatin, one of Southeast Asia's most wanted militants who helped plot the October 2002 suicide bombings in Bali that killed 202 people, had been linked al-Qaida in Aceh, a new jihadist group that has sprung up in the northernmost tip of Sumatra, an Islamic stronghold.

Dulmatin, an expert bomb maker, was gunned down six months after the U.S.-trained Detachment 88 killed his longtime associate, Noordin Top, in September 2009.

He was the leader of Jemaah Islamiya, the main jihadist group in Indonesia which has close links to al-Qaida.

Indonesian authorities have rounded up dozens of jihadist suspects since Feb. 22, when a raid on an AQA camp uncovered a wealth of intelligence that led to 15 other swoops.

Unlike Iraq's ISI, the Indonesian jihadists have yet to name a new leader to replace Dulmatin. The most likely candidate is another longtime associate, Umar Patek, a veteran field commander who is now Detachment 88's prime target.