Sequence of events that led to Saudi Arabia, UAE, Egypt and Bahrain severing diplomatic relations with Qatar.

Saudi Arabia, Egypt, the United Arab Emirates (UAE) and Bahrain severed their ties with Qatar on Monday, accusing it of supporting Islamist groups, opening up the worst rift in years among some of the most powerful states in the Arab world.

The coordinated move dramatically escalated a dispute over Qatar’s support of the Muslim Brotherhood, the world’s oldest Islamic movement, and added accusations that Doha even backs the agenda of regional rival Iran.

READ MORE: Qatar’s reaction in full

Announcing the closure of transport ties with Qatar, the three Gulf states gave Qatari visitors and residents two weeks to leave their countries.

Qatar was also expelled from a Saudi-led coalition fighting in Yemen.

Economic disturbances loomed immediately, as Abu Dhabi’s state-owned Etihad Airways, Dubai-based Emirates and flydubai said they would suspend all flights to and from Doha from Tuesday morning until further notice.

The measures are more severe than during a previous eight-month rift in 2014, when Saudi Arabia, Bahrain and the UAE withdrew their ambassadors from Doha, again alleging Qatari support for armed groups. At that time, travel links were maintained and Qataris were not expelled.

A split between Doha and its closest allies can have repercussions around the Middle East, where Gulf states have used their financial and political power to influence events in Libya, Egypt, Syria, Iraq and Yemen.

The announcements come 10 days after President Donald Trump visited Riyadh to call on Muslim countries to stand united against armed groups, and singling out Iran as a key source of funding and support for armed groups.

Here is a timeline of the recent main events that led to the escalation of disputes between the GCC nations.

Yemen’s sacking of southern leaders

April 28, 2017: Tens of thousands of Yemenis protested in Aden against President Abd-Rabbu Mansour Hadi‘s sacking of the provincial governor and a cabinet minister widely praised for helping drive Iran-aligned Houthis from the city in 2015.

READ MORE: Qatar: ‘No justification’ for cutting diplomatic ties

The two men sacked, Aden provincial governor Aidarus al-Zubaidi and cabinet member Hani bin Brek, were both seen as supporting separatism for southern Yemen.

Zubaidi was one of the leaders of the Southern Resistance that helped expel the Houthis from his city.

Yemen accuses UAE of behaving like ‘occupation power’

May 2, 2017: President Hadi of Yemen accused the UAE of behaving “like an occupation power in Yemen rather than a force of liberation” in a meeting with the crown prince of Abu Dhabi Mohammed bin Zayed.

Trump arrives in Saudi Arabia

May 20, 2017: US President Donald Trump arrived in Saudi Arabia on the first leg of his first foreign trip since taking office to hold a series of meetings with the king and other Arab and Muslim leaders.

In a red-carpet airport welcome, Saudi King Salman bin Abdulaziz Al Saud greeted Trump, his wife Melania and his entourage shortly after they landed in the capital, Riyadh.

‘Give them hell’

May 22, 2017: The night before former US Secretary of Defense Robert Gates was scheduled to speak at a high-profile Washington conference on Qatar, the UAE’s ambassador to the US, Yousef al-Otaiba, using a nickname of UAE Crown Prince Muhammed bin Zayed emailed Robert Gates asking him to “give them hell”.

READ MORE: Riyadh summit discusses ways of rooting out terrorism

May 23, 2017: The next day, Gates offered a scathing assault on Qatar, criticised its support for “Islamists”, at an event hosted by the hawkish Foundation for Defense of Democracies (FDD).

“Tell Qatar to choose sides or we will change the nature of the relationship, to include downscaling the base,” Gates said.

Hacking of Qatar News Agency

May 24, 2017: Qatar News Agency was targeted by hackers with “fake” comments purportedly criticising US foreign policy attributed to Emir Sheikh Tamim bin Hamad Al Thani on Qatar News Agency (QNA) platforms that sparked a regional media war.

Qatar denied the statement attributed to the emir, purportedly criticising US foreign policy. The emir’s false remarks were picked up by Saudi and UAE media, and sparked angry responses in Riyadh and Abu Dhabi.

FBI help Qatar in QNA hacking investigation

June 2, 2017: The US Federal Bureau of Investigation arrived in Doha after the Qatari government asked the United States for help following the security breach by hackers the previous month on its official media platform, QNA.

Hackers leak emails

June 3, 2017: Hackers released the first series of emails which were taken from the inbox of the UAE’s ambassador to the United States, Yousef al-Otaiba, including the email to Robert Gates on May 22.

The Intercept reported that the emails, released by a group called “Global Leaks”, show a close relationship between Otaiba and a pro-Israel, neoconservative think-tank – the FDD.

READ MORE: GCC rejects formation of Yemen transitional council

Saudi Arabia, Egypt, UAE sever ties with Qatar

June 5, 2017: Several nations cut diplomatic ties after Saudi Arabia, Egypt, UAE and Bahrain announced they would suspend relations with the Gulf state.The Saudi kingdom made the announcement via its state-run Saudi Press Agency, saying it was taking action for what it called the protection of national security.

The news agency released a statement in which it accused Qatar of “harbouring a multitude of terrorist and sectarian groups that aim to create instability in the region”.

Reacting to the fallout, Qatar explained that the decision was in “violation of its sovereignty”, vowing to its citizens and the hundreds of thousands of residents that the measures would not affect them.