The Paris attacks on Friday came at the end of a week in which Islamic State militants claimed responsibility for a number of terrorist attacks around the world.
Thursday and Friday saw a number of major attacks carried out by the militant group - as well as some significant developments in the continued fight against IS in Iraq and Syria.
On Thursday, 45 people were killed and around 200 injured in Lebanon when a pair of suicide bombings hit the capital Beirut.
The attacks happened minutes apart at a Shia community centre and nearby bakery in the Borj al Barajneh area during the evening rush hour.
In a statement posted on Twitter, Islamic State said its members detonated a bike loaded with explosives and when people gathered a suicide bomber blew himself up among them
A Lebanese security official gave a different version of events to IS, saying the first attacker set off his explosives vest outside the community centre, while the second blew himself up inside the bakery.
An apparent third suicide bomber was found dead, his legs blown off, wearing an intact explosives' belt, the official added.
Southern Beirut is a stronghold of Lebanon's militant Hezbollah group, which is fighting in Syria alongside president Bashar al Assad's forces.
The area has been targeted in the past by Sunni extremists over Hezbollah's involvement in Syria, but the latest attack is the first since June 2014.
Hezbollah denounced it as a "crime" and vowed to continue its fight against "terrorists".
The country held a day of national mourning on Friday following the bombings.
In a statement, the White House denounced the bombings, saying the "United States will stand firm with the Government of Lebanon as it works to bring those responsible for this attack to justice.
"Such acts of terror only reinforce our commitment to support the institutions of the Lebanese state, including the security services, to ensure a stable, sovereign, and secure Lebanon".
In Iraq, Islamic State claimed responsibility for an attack in Baghdad on Friday that killed at least 26 people and injured dozens of others.
The suicide bomber targeted a memorial for Shiite militia fighter, who had been killed in a separate attack on a Baghdad suburb that left at least 21 dead. Islamic State also claimed responsibility for that bombing.
Separately, the New York Times reports that a roadside bomb detonated at a Shiite shrine in Sadr City, killing five people and wounding more than a dozen others.
At least 129 people were killed and hundreds injured in Paris following a series of co-ordinated attacks in the French capital on Friday night.
Islamic State has claimed responsibility for the multiple attacks - and has warned that France would remain at the "top of the list of targets" over its airstrikes on IS territory in Syria and Iraq.
You can find a full timeline of the Paris attacks here.
However this week also saw a number of notable developments in the fight against Islamic State.
Ahead of the attacks in Paris on Friday, it was widely reported that a drone strike targeting the British IS militant known as "Jihadi John" had been carried out in Syria - and the US was "99% sure we got him".
'Jihadi John' - real name Mohammed Emwazi - is the name that was given to the man seen executing a number of hostages in a series of IS propaganda videos, including the ones showing the beheadings of US journalist James Foley and UK hostages Alan Henning and David Haines.
Eyewitnesses in Raqqa said Jihadi John was taken to hospital after the strike, with Islamic State claiming he was injured but still alive.
Although the official line from IS leaders was that Emwazi survived, locals say the hospital was then closed to the public - with claims that only happens when a senior militant has been killed.
A Pentagon spokesman said later it was "reasonably certain" he had been killed by a Hellfire missile.
The Pentagon says an airstrike in Libya targeted another senior IS figure on Friday - Abu Nabil, also known as Wissam Najm Abd Zayd al Zubaydi.
Press secretary Peter Cook said, "Nabil's death will degrade ISIL's ability to meet the group's objectives in Libya, including recruiting new ISIL members, establishing bases in Libya, and planning external attacks on the United States."
Meanwhile Kurdish fighters also took control of the strategically important town of Sinjar in northern Iraq, after taking it from Islamic State.
US-led coalition airstrikes supported the offensive, dubbed Operation Free Sinjar.