The Group to Support Islam and Muslims bragged about killing Westerners and attacking "a site of debauchery"
They fear that new groups will join the conflict after Eid al-Fitr.
The Department of Homeland Security and the FBI had warned about vehicle-ramming attacks, but this method is usually associated with Islamist extremists and jihadis.
Monday's attack targeted worshippers from an institution with a proud history of fighting violent extremism.
Pakistan is refusing to take sides in the diplomatic dispute between Saudi Arabia and Qatar, but has agreed to take certain steps to defuse tensions.
Deputy Chief of Staff of Iranian Armed Forces Major General Mostafa Izadi said Tehran has evidence of the U.S.'s "direct support" for the Islamic State militant group.
Decades of terrorism in Africa show that heavy-handedness is not the solution to a rising militant threat.
Figures released by Mayor of London Sadiq Khan show as many as 20 incidents per day.
Khuram Butt and Rachid Redouane were "warned about their conduct" after wrestling in the water.
The traditional strategy of "contain and negotiate" in hostage situations been scrutinised after "lone wolf" attacks.
The statement follows the first major ISIS attack on Iranian soil.
Twitter users shared photos and stories after Saudi Arabia, the UAE and Bahrain implemented an embargo on Qatar Monday.
Deadly attacks in London and Manchester had perpetrators known to intelligence. Did tight budgets hinder security services in preventing the violence?
The divisions in the East End community have turned it into a flashpoint between white nationalists and radical Islamists.
"We are friends," Trump told Qatar's leader during a filmed meeting. "And one of the things that we will discuss is the purchase of lots of beautiful military equipment."
Putin's spokesman said Moscow wants to hear Trump's opinion after his deputy accused Russia of "efforts to redraw international borders by force."
Trump's son claimed CNN and other media outlets staged a protest of Muslims condemning ISIS.
Police have already named the other two attackers as Khuram Butt and Rachid Redouance.
The war has lasted for 14 days in the southern island of Mindanao.
Oscar Munoz says the risk of a laptop bomb being detonated in a plane hold appears remote.