Israeli airstrikes on Gaza kill senior figure in Palestinian militant group.

Airstrikes break lull that followed wave of violence in West Bank and Israel.

TEL AVIV — Israeli airstrikes hit several targets in the Gaza Strip on Friday, killing a number of people including a senior commander of a Palestinian militant group, in the deadliest escalation of violence in the territory since an 11-day war last year.

One airstrike killed Taysir al-Jabari, a senior military leader in Islamic Jihad, the second-largest militant group in Gaza, according to both Islamic Jihad and the Israeli military.

Both Israel and Hamas, the militant group that dominates Gaza, had signaled they sought to avoid another full-scale war over the enclave, which has been under an Israeli and Egyptian blockade since 2007.

The airstrikes followed almost a week of rising tensions between Israel and Islamic Jihad, which often acts independently of Hamas.

Israel closed crossings into the Gaza Strip this week in anticipation of a retaliatory attack following the arrest in the West Bank.

After the airstrikes, Islamic Jihad said it would respond with force, and cities in southern Israel opened bomb shelters in anticipation of rocket fire from Gaza.

Islamic Jihad, a militant group in the Gaza Strip targeted earlier by Israel, claimed responsibility for the rocket fire.

diplomats to persuade Islamic Jihad to limit its response, and to urge Hamas, the militant group that runs the Gaza Strip, to remain on the sidelines of the latest round of violence, according to a senior Western diplomat speaking on condition of anonymity.

The earlier Israeli airstrikes on Gaza targeted militants from Islamic Jihad, a smaller group that often acts independently of Hamas and does not necessarily have Hamas’s backing.

Israeli officials including Yair Lapid, the interim prime minister, have said that the initial Israel airstrikes were a specific pre-emptive response to an imminent attack by Islamic Jihad.

Israeli authorities closed both crossings between Israel and Gaza, including the only commercial crossing, earlier this week after it said it received intelligence about a planned attack by the Palestinian Islamic Jihad.

The small militant faction Palestinian Islamic Jihad was at the center of a new flare-up in violence between Israel and the Gaza Strip on Friday.

Airstrikes on Gaza followed almost a week of rising tensions between Israel and Islamic Jihad.

Israel arrested one of the group’s senior commanders in the West Bank this week, leading to threats of reprisal from its Gaza leadership.

The second-largest militant group in Gaza, Islamic Jihad has often been eclipsed by the larger Hamas movement, which has controlled and governed Gaza since 2007.

Islamic Jihad was founded in the 1980s in the Gaza Strip and maintains a presence in Gaza and the Israeli-occupied West Bank.

Hamas and Islamic Jihad are sometime rivals that coexist in the tiny coastal enclave of Gaza, often uniting against their common enemy, Israel.

The airstrikes on Gaza on Friday followed a year in which the focus of Israeli-Palestinian violence had been in the occupied West Bank and Israel.

Several civilians have been caught in the violence, including Shireen Abu Akleh, a Palestinian American broadcaster shot dead while covering an Israeli raid in the West Bank city of Jenin in May.

But while Hamas, the militant group that seized control of Gaza in 2007, encouraged the unrest in Jerusalem and called for more attacks in the West Bank, it consistently signaled that it was not seeking an eruption of violence in Gaza itself.

The militant group Hamas remains in control of Gaza, where it provides safe haven for other groups like Islamic Jihad and threatens Israeli towns with an arsenal of rockets.

The spark for the conflict was not in Gaza but in East Jerusalem, which Israel seized in the 1967 war and claims as its own, but which Palestinians say should become the capital of a future Palestinian state on the West Bank.

The eruption of violence on Friday comes less than a month after President Biden paid his first visit as president to Israel and the West Bank, offering words of support to both sides but no steps toward peace between them.