How Islamic State called for 'all-out war' on West during Ramadan

European security services are bracing for more attacks during the Muslim holy month of Ramadan, which began on May 27th, after Isis (Islamic State) called on its followers to rise up in an "all-out war" on "infidels" in the West.

Last Saturday marked the start of a 30-day period of fasting and reflection in the Islamic world, which has in recent years seen a large uptick in Isis terror attacks.

"Muslim brothers in Europe who can't reach the Islamic State lands, attack them in their homes, their markets, their roads and their forums," the jihadist group said in a message entitled Where are the lions of war? and published on YouTube.

Defending themselves after the suicide attack on Manchester Arena, which left 22 mostly children and teenagers dead, the group said: "Do not despise the work. Your targeting of the so-called innocents and civilians is beloved by us and the most effective, so go forth and may you get a great reward or martyrdom in Ramadan."

It is not yet known if Isis were behind this weekend's London terror attack, if they inspired it, or whether other groups were responsible. However, it is highly likely that Islamic jihadists were to blame given witness accounts of the attackers screaming "This is for Allah" as they carried out their atrocity.

Last year, Abu Mohammed al-Adnani, the late Isis spokesman, issued a call to arms to followers to carry out lone wolf attacks during the holy month. It was the bloodiest Ramadan month on record.

Isis took credit for a lone jihadist gunman, an Afghan American who perpetrated America's deadliest mass shooting in history and worst terrorism on US soil since 9/11 during early morning hours of June 12 at an Orlando gay nightclub, killing 49 and wounding 53.

An Islamist jihadist then stabbed a police officer and his wife in a Paris suburb in front of their son. The killer explicitly claimed in a live broadcast of the murder that he was responding to Adnani's call.

Later that month, three Isis suicide bombers opened fire then blew themselves up at Istanbul's main airport, killing 45 and wounding more than 250.

The final global body count after the month-long rampage was 421 dead and 729 wounded.

Hitting multiple targets in many different countries is designed to send the message that no person on earth is safe or can be protected from terrorism.

As countries have tightened borders around the world making it harder for militants to slip in and out of Isis' so-called caliphate, the terror group has modified its message to encourage supporters to carry out terror attacks in their home countries.

A recent report from the Washington-based Institute for the Study of War argued that Isis is seeking to use Ramadan "as an occasion to reorient its strategy" with attacks in its core arena of operations in Iraq and Syria and abroad.

It is feared a network linked to Salman Abedi, the 22-year-old suspected Manchester bomber, is still active in the UK and could have enough explosive material for another attack.

On Friday, the search for his Islamist cell was continuing with a total of eight people being questioned on suspicion of involvement in what officers described as "significant arrests".