Saudi Arabia, Egypt, Bahrain and UAE have severed diplomatic ties with Qatar amid a simmering row among US allies in the region.

The three countries said they will suspend air and sea travel to and from Qatar. Saudi Arabia said it will shut land crossings with its neighbor, according to the official Saudi Press Agency. Bahrain has given Qatari diplomats 48 hours to leave.

Saudi Arabia said the move was necessary to protect the kingdom from what it described as terrorism and extremism. The kingdom also pulled all Qatari troops from the ongoing aggression in Yemen.

The official state news agency, citing an official source, said Saudi Arabia had decided to sever diplomatic and consular relations with Qatar proceeding from the exercise of its sovereign right guaranteed by international law and the protection of national security from the dangers of terrorism and extremism.

Saudi Arabia cut all land air and sea contacts with Qatar and urges all brotherly countries and companies to do the same.

Bahrain announced early Monday that it is severing diplomatic relations with neighboring Qatar and cutting air and sea connections with Doha, accusing it of meddling in its internal affairs.

Bahrain's state news agency said in a brief statement that Qatari citizens have 14 days to leave the country. It accused Doha of supporting terrorism and meddling in Manama's internal affairs.

Egypt's state news agency also announced the country was cutting ties with Qatar, accusing it of supporting terrorist groups.

The United Arab Emirates' decision to cut ties with Qatar was reported by state news agency WAM, accusing its Persian Gulf Arab neighbor of supporting extremism and undermining regional stability.

The Emirates gave diplomats 48 hours to leave the country, citing their support, funding and embrace of terrorist, extremist and sectarian organizations, WAM said.

Qatar has reacted by calling the decision by the three Persian Gulf nations and Egypt 'unjustified', saying allegations against Doha have no basis in fact.

The current row started after a statement posted on Qatar's news agency on 24th May threw into disarray the façade of unity that was created at the recent Riyadh summit attended by US president Donald Trump.

The report criticized Saudi Arabia for fueling tensions with Iran prompting a sharp response from Riyadh and its allies. Doha has blamed unidentified hackers for breaking into the agency's website and publishing fake news.

Qatari officials also claimed hackers took over the news agency's Twitter feed and posted alleged quotes from Qatar's foreign minister accusing Arab nations of fomenting a plot against his country.

The latest incident is not the first time Arab countries are breaking ties with Qatar. In March 2014 Saudi Arabia, the United Arab Emirates and Bahrain broke ties with Qatar over its backing of then-Egyptian President Mohammed Morsi, a Muslim Brotherhood member. Eight months later, they returned their ambassadors after Qatar forced some Brotherhood members to leave the country and silenced others.