More attacks should be expected internationally in the next two weeks during Ramadan, a terrorism expert is warning.
The month of fasting, which lasts until 24 June, is observed by the Islamic religion.
Sajjan Gohel of the Asia Pacific Foundation, a London-based think tank, said the Islamic State group had targeted the month for more attacks.
"They have hijacked Ramadan for the last two years."
"Most recently they have issued a message to call on their followers to, quote, 'carry out an all-out war' on infidels in the West.
"A very chilling message, they said to attack them in their homes, markets, roads and forums."
Dr Gohel said the style of terrorism had now changed, with in the past the IRA giving warnings ahead of the attack, to Al Qaeda's 9/11 attack.
Those types of attacks focused on large-scale attacks on buildings, but leaks and large cells often resulted in the attacks being prevented by authorities.
Islamic State often used low-tech methods, such as the van attack in London, and Dr Gohel said that type of warfare could be very effective in creating fear.
"In many ways they're more effective, because they keep it simpler - turning a vehicle into a lethal weapon, carrying out mass stabbings."
"These may not kill hundreds of thousands of people but they do create disruption, they do create fear and panic, and it's the visualisation that ISIS also focuses on as their oxygen of publicity.
"Very often these attacks are streamed by people witnessing these attacks and in many ways that is the notoriety that ISIS wants and courts."