The killing of Islamic State leader Abu Bakr al-Baghdadi is a further blow to a jihadist group that once held a swathe of territory in Iraq and Syria, experts said, but the organisation and its ideology remain dangerous.
Where once they confronted armies, the extremist Islamist group’s adherents have recently staged hit-and-run and suicide attacks. In some cases, the group claimed responsibility for atrocities including bombings in Sri Lanka in April that killed more than 250 people.
Islamic State’s involvement is not always proven, but even if the link is ideological rather than operational, it is still a security threat in many countries:
After defeat by US-backed forces, Islamic State reverted to the guerrilla tactics it was once known for.
Iraqi Security Forces routinely carry out operations against remnants of the Jihadist group, more than two years after its defeat.
Sleeper cells regrouped in provinces including Diyala, Salahuddin, Anbar, Kirkuk and Nineveh, where they carry out frequent attacks, including kidnappings and bombings aimed at undermining the Baghdad government.
Cells operate mostly in rural areas, burning crops and extorting local farmers, in February, two people were killed and 24 wounded when a car bomb went off in Mosul, once the group’s capital in Iraq.
The Pentagon said in January IS was regenerating faster in Iraq than Syria. Analysts estimated about 2 000 active combatants now operate in Iraq.
After serious military setbacks, Islamic State slipped into the shadows, staging suicide bombings and ambushes. It carried out bomb attacks in towns and cities in northern Syria in the past year and targeted US forces.
Syrian Kurdish forces, who crushed the jihadists across the north and east with US help, believe sleeper cells mushroomed in eastern Syria. They warn of the risk posed holding thousands of militants in prisons, including foreigners.
That warning came into sharp focus when US President Donald Trump withdrew US troops from Syria, opening the way for Turkey to launch an offensive targeting Kurdish fighters.
Turkey says it captured about 200 IS detainees who fled prisons and transferred them to other prisons under control of Turkish forces and Syrian rebel allies. President Tayyip Erdogan said IS prisoners will be brought to justice.
Egypt has had no major attacks over the past year, but smaller incidents persist and the military is mounting a campaign against Islamist insurgents, mainly on the Sinai Peninsula.
The military says several hundred militants were killed since it launched a campaign in February 2018 to defeat fighters linked to Islamic State in Sinai.
A Russian passenger jet was bombed shortly after take-off from Sharm el-Sheikh in 2015, killing all 224 people on board. The attack was claimed by Islamic State.
Islamic State militants carried out bombings and shootings in Saudi Arabia against security forces and minority Shi’ite Muslims, after authorities crushed an al Qaeda insurgency more than a decade ago.
Baghdadi called for attacks against Saudi Arabia when the kingdom joined the US-led coalition mounting air strikes against his group. In his speeches, he used derogatory terms referring to rulers in Riyadh.
Kamran Bokhari, a director at Washington-based think-tank the Centre for Global Policy, said Islamic State exists in the kingdom but Saudi security forces and intelligence are “pretty much on top of things”.
Islamic State militants announced a Yemeni affiliate in late 2014 as the country descended into civil war between the Saudi-backed government of Abd-Rabbu Mansour Hadi and the Iran-aligned Houthi movement.
The group faced tough resistance from Al Qaeda’s local branch, Al Qaeda in the Arabian Peninsula (AQAP), and both groups fought, especially in al-Bayda. Al Qaeda and Islamic State also fight Shi’ite Houthis, which they see as heretics.
Islamic State claimed several assassinations and bombings in south Yemen but has never held territory. Experts believe Al Qaeda, with older and deeper tribal connections, poses a bigger threat.
Nigerian group Boko Haram carried out attacks in north-eastern Nigeria since 2009 in pursuit of an Islamic caliphate. It killed more than 30 000 and forced two million to flee their homes. The group split in 2016 and one faction pledged allegiance to IS.
Islamic State’s West Africa Province (ISWAP) focused on attacking military bases in raids over the last year. It is the dominant militant group in the region.
The extent of support provided by Islamic State to ISWAP is unclear and security experts say the relationship is in name rather than funding and logistic support.
Islamic State in Khorasan (ISIS-K), which took its name from a historical region that covered much of modern-day Afghanistan and parts of Central Asia, appeared in late 2014 in the eastern province Nangarhar, where it retains a stronghold. It announced its formation in January 2015.
The group’s leadership pledged allegiance to Baghdadi but it is not clear if ISIS-K has direct operational links with the main movement.
It claimed attacks on civilian targets in cities including Kabul and fought the Afghan Taliban for control of rural districts. US commanders say its forces number fewer than 2 000.
The movement is little understood and Afghan officials doubt the veracity of some of its claims.
Islamic State claimed the Easter Sunday bomb attacks on churches and hotels in April and released a video showing eight men declaring loyalty to Baghdadi.
IS claimed the men in the video, released by its Amaq news agency, carried out the suicide bombings.
Sri Lankan officials blamed domestic Islamist groups with suspected ties to Islamic State.
Indonesia is the world’s most populous Muslim-majority country and most people practise a moderate form of Islam. There has been a resurgence in militancy and authorities believe thousands of Indonesians draw inspiration from Islamic State, while about 500 Indonesians are thought to have gone to Syria to join the group.
A court sentenced cleric, Aman Abdurrahman, to death last year for masterminding deadly attacks. Abdurrahman is considered the ideological leader of Jemaah Ansharut Daulah (JAD) – a loose grouping of Islamic State sympathisers in Indonesia.
Suicide bombings in May last year in Surabaya that killed more than 30 people were linked to JAD cells.
The Philippines fears extremists fleeing Iraq and Syria could find a safe haven in the jungles and remote villages of Muslim areas of Mindanao, where there is a long history of lawlessness, clan rivalry and separatist and Islamist rebellion.
Splinters of myriad armed groups in southern Philippines pledged allegiance to Islamic State, although none are known to have been endorsed as its Southeast Asian affiliate.
Islamic State claimed responsibility for bombings and rebel clashes with government troops in Mindanao, but their veracity is disputed.