Israeli officers on Sunday sealed off the Jerusalem family home of a Palestinian gunman who killed seven people outside a synagogue on the outskirts of the city, police said, after Prime Minister Benjamin Netanyahu promised “a swift response”.

Seven people including a 14-year-old were shot dead on Friday in the attack on International Holocaust Remembrance Day, which drew wide international condemnation and heightened fears of already spiralling violence escalating further.

It was the worst such Palestinian attack on Israelis in the Jerusalem area since 2008 and followed a fatal Israeli raid in the occupied West Bank city Jenin on Thursday, the deadliest there in years.

The shooting presents a challenge to Netanyahu, who returned to power in December at the head of a hard-right nationalist government, promising to improve personal safety for Israelis after a spate of lethal Palestinian street attacks last year.

The Israeli military said on Saturday it was sending additional troops into the West Bank, which has seen months of worsening clashes that culminated in 2022 with the highest death toll, including militants and civilians, in more than a decade.

Still, there was no sign Israel was preparing for a large-scale military response to the shooting. With U.S. Secretary of State Anthony Blinken visiting this week, Israeli and Palestinian leaders were expected to try to contain violence.

After convening his security cabinet for a late night meeting on Saturday, Netanyahu said the government would pursue sanctions against families of assailants and that he would present steps this week to “strengthen settlements”.

Sworn in a month ago, Netanyahu’s government – the most right-wing in Israel’s history – has prioritised settlement building on lands the Palestinians seek for a state, though it has not yet taken major steps on the ground in that direction.

Most world powers consider as illegal Israel’s settlements in the West Bank and East Jerusalem, land it captured in the 1967 war.

Palestinian President Mahmoud Abbas has not remarked on Friday’s attack and on Saturday blamed Israel for the spiralling violence. The gunman had apparently acted alone and was shot dead by officers as he tried to flee the scene, police said.