The attack by Hamas on Israel on 7 October will inspire the most significant terror threat to the US since the rise of Islamic State (IS) nearly a decade ago, the FBI director, Christopher Wray, said at a congressional hearing in Washington on Tuesday. Wray said that since the start of the Israel-Palestine conflict earlier this month, multiple foreign terrorist organizations have called for attacks against Americans and the west, significantly raising the threat posed by homegrown US violent extremists. “The actions of Hamas and its allies will serve as an inspiration the likes of which we haven’t seen since Isis launched its so-called caliphate several years ago,” Wray said. Hamas killed at least 1,400 people in southern Israel when they broke through border barriers with Gaza on 7 October, and also took more than 200 hostages. Israel first responded with a sustained aerial bombardment of Gaza and a blockade of supplies including food, water, medicine and fuel. It has now entered north Gaza, expanding attacks to a ground war. The Israeli military has killed more than 8,000 people, mostly civilians, including thousands of children. With the region in crisis, Wray’s remarks came during a hearing before the US Senate homeland security and governmental affairs committee focused on threats to the United States. The US government has seen an increase in threats against Jewish, Muslim and Arab Americans since fighting broke out in Gaza, officials have said. The number of attacks on US military bases overseas by Iran-backed militia groups have risen this month, Wray said. Iran supports Hamas and also sponsors the anti-Israeli group Hezbollah based in Lebanon, on Israel’s northern border. Cyber-attacks against the US by Iran and non-state actors will likely worsen if the conflict expands, he said. Iran’s mission to the United Nations did not immediately respond to a request for comment. During the hearing, the homeland security secretary, Alejandro Mayorkas, said that hate directed at Jewish students in the US following the fresh descent into crisis in the Middle East has added to an increase in antisemitism, a view echoing warnings by the White House. Attorney general Merrick Garland, meanwhile, has directed the US justice department to assist Israeli investigators probing financial flows to Hamas.