Prime Minister Theresa May will leave the Group of Seven gathering in Sicily a day early to return to the UK as the country races to prevent further terrorist attacks from the network behind the Manchester suicide bombing.

Axar.az reports citing Bloomberg.

The premier travels to Brussels on Thursday for a Nato summit, where she will urge the alliance to fully join in the fight against Islamic State and tackle what she’s called “poisonous” online material that radicalizes young Muslims, according to a UK government official.

She was then due to travel to Sicily for the G7 meeting until Saturday but will now leave Italy on Friday evening, the official said, speaking on condition of anonymity because the travel plans aren’t public. The decision to cut short her attendance at the G7 was driven by the fact that Britain is under its gravest threat from terrorism in a decade, the official said.

“We must redouble our resolve to meet the threats to our shared security whether from terrorism or Russia,” May will tell the North Atlantic Treaty Organization (Nato) summit participants, according to extracts of her address released by the UK official.

The prime minister will say a “strong, capable and united Nato is at the heart of the security of each and every one of our nations,” adding that “our unity against common threats is our most potent weapon.”

British security forces are frantically hunting other members of the terror network they believe collaborated with the Manchester bomber Salman Abedi, who killed 22 people including children when he blew himself up at a pop concert on Monday. Abedi’s father and younger brother were detained by security personnel in the Libyan capital, Tripoli, on Wednesday, according to witnesses and officials.

The suicide bombing was the deadliest on UK soil since the 2005 London bombings. May will tell fellow Nato members that the alliance should formally commit itself to the coalition fighting Islamic State in Iraq and Syria.

The prime minister will also point to the “callous and cowardly” Manchester bombing as an example of why the international community, including Nato, must do more in the fight against terrorism, the official said. Nato members will debate formally committing the alliance to the fight against Islamic State on Friday.