Israel carried out airstrikes on targets in Gaza early Tuesday morning, killing three leading members of the militant group Islamic Jihad, according to the Israeli military.

Palestinian health officials in Gaza said at least 12 people had been killed, including the commanders, their wives and several of their children, and that 20 people were injured.

The Israeli military said "Operation Shield and Arrow" had killed Khalil Bahtini, Islamic Jihad's commander for the northern Gaza Strip, Tareq Izzeldeen, the intermediary for the group's branches in Gaza and the West Bank, and Jehad Ghanam, secretary of the group's military council.

"Any terrorist who harms Israeli citizens will be made to regret it," said Israeli Defense Minister Yoav Gallant.

Islamic Jihad — an Iranian-backed group that pales in comparison to the larger Hamas militant group that dominates the Gaza Strip — also confirmed that the three senior figures were among the dead, adding in a statement, "We will not abandon our positions and the resistance will continue, God willing."

The European Union, United States and several other nations list Islamic Jihad as a terrorist organization.

Early morning airstrikes

Israel said the named men targeted in the airstrikes had been responsible for firing rockets into Israel.

The predawn attack hit a top-floor apartment in Gaza City as well as a house in Rafah. The airstrikes reportedly carried on into the early hours of the morning as the Israeli military struck militant training grounds.

Residents of Israeli communities within 25 miles (40 kilometers) of the border with Gaza were told to be ready to seek shelter in bomb shelters in case retaliatory rockets were fired from Gaza.

The airstrikes came at a time of already high tension between Israel and militants in the Gaza Strip, which increased again last week after a senior member of Islamic Jihad died while on a hunger strike in Israeli custody. Following his death, militants fired several salvos of rockets toward southern Israel, and Israel responded with airstrikes.

That episode had ended with a truce brokered by Egypt, the UN and Qatar.

More than 100 Palestinians — of which around half were believed to be militants — and at least 19 Israelis have been killed this year.

Israel says raids in the West Bank are meant to dismantle militant networks and prevent future attacks.