GAZA CITY, GAZA STRIP -- Israel carried out a series of targeted airstrikes in densely populated areas of the Gaza Strip early Tuesday, killing three senior commanders of the Islamic Jihad militant group and at least 10 civilians, Palestinian health officials said. Two of the commanders' wives, several of their children and other bystanders were among the dead.

The attacks set the stage for what is likely to be a new round of heavy fighting. They hit the top floor of an apartment building and a house in Gaza City, and a third house in the southern town of Rafah. The Palestinian Health Ministry said 20 people were wounded, and that some were in serious or critical condition.

Israel said it targeted several militant training sites as well before the airstrikes halted at daybreak.

At midday, tens of thousands of people took part in two funerals, with at least 10 bodies being mourned in one funeral in Gaza City. Mourners carried the bodies, which lay on stretchers, on their shoulders to ambulances. Children's coffins were carried next to those of their parents.

Such targeted killings are rare, and in the past, Palestinian militant groups have retaliated with heavy barrages of rocket fire.

In anticipation of renewed rocket fire, the Israeli military advised residents of communities within 25 miles (40 kilometers) of Gaza to stay close to designated bomb shelters.

Israel's Home Front command ordered the closure of schools, beaches and highways in cities and towns in southern Israel, and limited public gatherings.

The military said the three targeted men had been responsible for recent rocket fire toward Israel.

It identified them as Khalil Bahtini, the Islamic Jihad commander for northern Gaza Strip; Tareq Izzeldeen, the group's intermediary between its Gaza and West Bank members; and Jehad Ghanam, the secretary of the Islamic Jihad's military council.

The Iran-backed Islamic Jihad, which is smaller than Gaza's ruling Hamas group, confirmed the three were among the dead.

In its statement, the group said the wives of the three commanders were killed, but witnesses and family members said the wives of only two commanders were killed. The Palestinian Health Ministry said the 13 dead included four women and four children.

The Russian diplomatic delegation in Ramallah, in the West Bank, said that one of the men killed, Jamal Khaswan, was a Russian national, and that his wife and son were also killed. Khaswan was a dentist who lived downstairs from Izzeldeen in Gaza City.

The Israeli airstrikes drew condemnation from Palestinian Prime Minister Mohammed Shtayyeh, Jordan's foreign ministry and the Egyptian government, which often mediates between Israel and Palestinian militant groups in the Gaza Strip.

Tor Wennesland, the UN envoy to the Mideast, said he was 鈥渄eeply alarmed鈥 and condemned the civilian deaths, calling on all sides 鈥渢o exercise maximum restraint.鈥

Dawood Shahab, an Islamic Jihad official, said that there would be a 鈥渦nified Palestinian response鈥 to the strikes at a time and place of its choosing.

Hamas leader Ismail Haniyeh warned that Israel will 鈥減ay the price鈥 for the killings. 鈥淎ssassinating the leaders with a treacherous operation will not bring security to the occupier, but rather more resistance,鈥 Haniyeh, who lives in exile, said in a statement.

Islamic Jihad and Hamas are both Iranian-backed groups that oppose Israel's existence and possess large arsenals of rockets and other weapons.

In recent years, the larger and more powerful Hamas has stayed mostly on the sidelines, while allowing Islamic Jihad to carry out attacks. Islamic Jihad bombarded Israel with dozens of rockets last week after one of its members in the West Bank died from a hunger strike while in Israeli custody.

Islamic Jihad, however, says it coordinates its responses with Hamas as part of the so-called the Joint Operation Room, a Hamas-influenced umbrella of militant groups in Gaza. Islamic Jihad is closer to Iran than Hamas.

If Hamas joins the fighting, it would likely trigger an even heavier Israeli response. Two years ago, Israel and Hamas fought an 11-day war in which more than 250 Palestinians were killed and Israel toppled homes and high-rise buildings in the coastal enclave. Thirteen people in Israel also were killed.

Israel's defense minister, Yoav Gallant, told municipal leaders in southern Israel that 鈥渨e must be prepared for every eventuality, including a prolonged campaign and widening ranges of fire,鈥 his office said.

The airstrikes came at a time of boiling tensions between Israel and militants in Gaza. It is linked, in part, to increasing violence in the occupied West Bank, where Israel has been conducting near-daily raids for months to detain Palestinians suspected in planning or carrying out attacks on Israelis. Islamic Jihad members are frequent targets of the raids.

Last week, Gaza militants fired several salvos of rockets toward southern Israel, and the Israeli military responded with airstrikes following the death of tje jimger striker. The exchange of fire ended with a fragile cease-fire mediated by Egypt, the United Nations and Qatar.

The airstrikes are similar to ones in 2022 in which Israel bombed locations housing commanders of Islamic Jihad group, setting off a three-day blitz that saw the group lose its two top commanders and other dozens of militants.

Israel says the raids in the West Bank are meant to dismantle militant networks and thwart future attacks. The Palestinians see the attacks as further entrenchment of Israel's 56-year, open-ended occupation of lands they seek for a future independent state.

So far, 105 Palestinians, about half of them are militants or alleged attackers, were killed by Israeli fire in the West Bank and east Jerusalem since the start of 2023, according to an Associated Press tally. At least 20 people have been killed in Palestinian attacks in Israel in the same period.

Associated Press writer Ilan Ben Zion in Jerusalem contributed to this report.