GAZA CITY (Ma'an) -- A rocket fired from the Gaza Strip on Thursday struck an apartment building in southern Israel, killing three people after an Israeli airstrike killed two Hamas fighters and a security officer.
The deadly rocket attack was the first since Israel launched an air assault on the Gaza Strip a day earlier.
Early Thursday an Israeli attack killed a senior police official in the Gaza Strip government and two members of Hamas' military wing in early morning attacks, medics said.
Security commander Habes Masmah, 30, was targeted while riding a motorcycle east of Khan Younis, medics said. His body was taken to Nasser Hospital in Khan Younis.
Two members of Hamas' al-Qassam Brigades were also killed in the attack. They were identified as Wael Haidar al-Ghalban and Hisham Muhammad al-Ghalban.
Hamas' armed wing launched dozens of rockets into southern Israel, killing three people.
Israeli police said the three died when a rocket hit a four-story building in the town of Kiryat Malachi, some 15 miles north of Gaza. They were the first Israeli fatalities of the latest conflict.
The al-Qassam Brigades claimed responsibility for launching hundreds of projectiles including Katyusha rockets toward Ashkelon, Beersheva, Ashdod and south of Tel Aviv.
The group said it launched 10 Grad rockets at Ashkelon, 19 rockets toward Sufa and Nir Yitzhak, and five rockets toward Kiryat Gat near the Gaza border.
Islamic Jihad's armed wing as well as the Democratic Front's National Resistance Brigades said in separate statements that they launched attacks on Ashdod and Beersheva.
Israel on Wednesday assassinated Hamas's military mastermind and shelled the enclave from the land, sea and air, killing 13 people, including five militants, three children and a pregnant woman.
More than 100 were wounded.
The UN Security Council held an emergency meeting late on Wednesday to discuss the Israeli assault. It called for a halt to the violence, but took no action.
Expecting days or more of fighting, Israel warned Hamas that all its men were in its sights and dropped leaflets in Gaza telling residents to keep their distance from militants and Hamas facilities.
"The leaflets stress that Hamas is dragging the region toward violence, and that the IDF is prepared to defend the residents of the State of Israel until quiet is restored to the region," the military said in a statement.
Israel weathered censure from influential Arab powers Egypt and Qatar. The United States condemned Hamas, shunned by the West as an obstacle to peace for its refusal to renounce violence and recognise Israel.
Hamas has said the killing of its top commander, Ahmed al-Jaabari, would "open the gates of hell" for Israel. It also appealed to neighbouring Egypt to halt the "barbaric" assault.Reuters contributed to this report.