The Israeli bombing comes after rockets were fired from the Gaza Strip following the death of Khader Adnan earlier on Tuesday. Hamas media said Israeli planes hit two locations in Gaza city.

Adnan, who was awaiting trial, was found unconscious in his cell and taken to a hospital, where he was declared dead after efforts to revive him, Israel’s Prisons Service said on Tuesday.

Hundreds of people took to the streets in blockaded Gaza and the occupied West Bank to rally in support of Adnan and mourn his death, which Palestinian leaders described as an assassination.

The Israeli military said at least 26 rockets were fired from the enclave. Two landed in the southern city of Sderot, wounding three people, including a 25-year-old foreign national who Israel’s ambulance service said sustained serious shrapnel wounds.

An umbrella group of armed Palestinian factions, including Hamas and Islamic Jihad, claimed responsibility for rocket barrages towards Israel.

Earlier in the day, Tel Aviv fired artillery shells on several areas in the eastern parts of Gaza City and Khan Younis targeting the Malaka area specifically, Al Jazeera’s correspondent Heba Akkila said.

No casualties or damages have been reported yet.

In the West Bank city of Hebron, shops observed a general strike. Some protesters burned tyres and hurled stones at Israeli soldiers who fired tear gas and rubber bullets at them. There were no reports of injuries.

Israeli Prime Minister Benjamin Netanyahu met security officials to assess the situation. An Israeli military official said Israel would respond at a time and a place of its choosing.

Israel’s far-right National Security Minister Itamar Ben-Gvir said prison officials decided to close cells to “prevent riots”.

In a tweet, Israel’s Defence Minister Yoav Gallant said the security establishment will act with “determination and force” against those who harm the country.

Israeli observers said they believed an attack on Gaza to be imminent. “It is clear that there will an Israeli response. Expect intense air strikes in the next few hours,” Jackie Khouri, an Israeli affairs expert, told Al Jazeera from Haifa.

“I believe that the rules of the game will stay the same at this stage: As was the case last month, the intense air strikes on Gaza have not targeted residential areas.”

Al Jazeera’s Mohammed Jamjoom, reporting from West Jerusalem, said it would be surprising if Israel did not respond. Typically “they do so in the overnight hours – that would mean either later tonight or very early tomorrow morning,” he said.

Administrative detention

Mustafa Barghouti, general secretary of the Palestinian National Initiative (PNI), called the death of Khader Adnan an “ugly assassination” whose purpose is to “break the spirit of resistance that Palestinian prisoners have”.

Administrative detention is a mainstream measure whereby Palestinians are forcibly arrested without even knowing what they are been accused of. Hunger strikes are often the last recourse.

It is “a complete mockery of international human rights law”, Barghouti said.

The number of Palestinian administrative detainees has risen to more than 1,000 over the past year, the highest number in two decades.

Israeli rights group B’Tselem has described the hunger strike of Khader Adnan as “a form of non-violent protest against his arrest and the injustices of the occupation”.

Lina Qasem-Hassan of Physicians for Human Rights in Israel said she saw Adnan on April 23, at which point he had lost 40kg (88 pounds) and was having trouble breathing but was conscious.

“His death could have been avoided,” Qasem Hassan said. Several Israeli hospitals had refused to admit Adnan after he made brief visits to their emergency rooms.

Since 2011, Adnan had conducted at least three hunger strikes in protest at detentions without charges by Israel. The tactic has been used by other Palestinian prisoners, sometimes en masse, but none had died since 1992.

Adnan’s lawyer Jamil al-Khatib and a doctor with a human rights group who recently met him accused Israeli authorities of withholding medical care.

“We demanded he be moved into a civilian hospital where he could be properly monitored. Unfortunately, such a demand was met by intransigence and rejection,” al-Khatib told Reuters.

Adnan, 45, was a baker and a father of nine from Jenin in the Israeli-occupied West Bank. Islamic Jihad sources said he was one of its political leaders.

The faction has a limited West Bank presence but is the second-most powerful armed group in Hamas-governed Gaza, where Israeli forces carried out bombing last August.