GAZA CITY (Ma'an) -- The death toll on the 16th day of Israeli military offensive on Gaza rose to 24 on Wednesday after an Israeli airstrike killed 70-year-old Hasan Abu Hein, 34-year-old Osama Abu Hein, and journalist Abd al-Rahman Abu Hein, 24, in the Shujaiyya neighborhood of Gaza City.
Several other people were also injured when Israeli forces bombarded a 700-year-old mosque known as al-Shamaa mosque (also known as Bab al-Darum) in the Zaytoun neighborhood of Gaza City before noon time.
More than 650 Palestinians -- the vast majority of whom have been civilians, including more than 160 children -- have been killed in the assault so far, while Israel has suffered 29 deaths, 27 of whom have been soldiers.
The Gaza Strip continued to be bombarded from air, land, and sea on Wednesday morning, a day after the the United Nations' Palestinian refugee agency UNRWA accused Israeli of shelling a UN school sheltering the displaced for the second time in two days.
"UNRWA condemns in the strongest possible terms the shelling of one of its schools in the central area of Gaza," it said in a statement.
"The location of the school and the fact that it was housing internally displaced persons had been formally communicated to Israel on three separate occasions. We have called on the Israeli authorities to carry out an immediate and comprehensive investigation."
During the offensive, more than 135,000 Gazans have fled their homes, seeking shelter in 69 schools run by UNRWA.
Palestinian Ministry of Health spokesman Ashraf al-Qidra on Wednesday said that the evacuation of dead bodies and injured people had been very slow in a number of areas because Israeli forces had impeded the movement of ambulances and rescue teams.
Al-Qidra highlighted that the total Palestinian death toll had risen to 647 on Wednesday morning, including 161 children and 35 elderly people.
More than 4,000 Palestinians had also sustained injuries in the assault, he said, while hospitals were running dangerously low on medical supplies amid the most deadly sustained Israeli assault on the besieged coastal enclave since 2008.
Israeli leaders on Tuesday hinted that the assault would not end until Hamas' entire tunnel network had been destroyed, suggesting that the goals of the offensive had shifted from halting rocket fire to undermining the group's military infrastructure more broadly.
Hamas, meanwhile, has demanded that any ceasefire include the lifting of the Israeli blockade, which has been in place for the last seven years and includes Israeli control over all imports, exports, and movement of people in the tiny coastal enclave.
Israel launched the assault earlier in the month after a sustained offensive on Hamas across the West Bank in June and early July in order to find three missing Israeli teenagers, which left 10 Palestinians dead, more than 130 injured, and 600 Hamas-affiliated individuals in prison.
The offensive -- which was accompanied by airstrikes on the Gaza Strip -- led to a sharp rise in rocket fire from the area into Israel.
24 dead Wednesday morning
Palestinian Ministry of Health spokesman Ashraf al-Qidra said on Wednesday that Nidal Hamad al-Ejla, 25, was killed and 30 others were injured, including two children with serious injuries, in Israeli shelling in the al-Shamaa area of Gaza City. The body and the injured were moved to al-Shifa medical center.
Muhammad Ziyad Habib, 30, was also killed in an Israeli attack on eastern Gaza City.
Palestinian medical sources said earlier that 12-year-old Rabee Qasim was killed and four other people injured when an Israeli shell hit a cart pulled by a donkey in the Bedouin village of Umm al-Naser in the northern Gaza Strip on Wednesday morning.
Ashraf al-Qidra said that at least five people were killed in the village of Khuzaa east of Khan Younis in the southern Gaza Strip early Wednesday as well.
Medical sources said that Adnan Ghazi Habib from al-Mughraqa neighborhood succumbed to wounds he sustained overnight.
In Khan Younis in the southern Gaza Strip, rescue teams pulled four dead bodies from the rubble of houses destroyed by Israeli airstrikes Tuesday night. Medical sources identified them as Muhammad Abu Riddiya, his wife, Shama, as well as Khalil Abu Jami and Husam al-Qarra.
Among the victims were two children Muhammad Mansour al-Bashiti, 7, and Zeinab Abu Teir. Bassam Abu Tueima, 23, Mahmoud Abu Tueima, 25, and a senior leader in the Democratic Front for the Liberation of Palestine Ismail Abu Tharifa were also killed.
Earlier on Wednesday morning, Israeli airstrikes and artillery shells killed 18-year-old Hamza Abu Anza in Khan Younis.
Ibrahim Abu Asi and Wisam al-Najjar succumbed to their wounds also in Khan Younis.
Four Palestinians were also killed in Beit Lahiya in the northern Gaza Strip in two separate Israeli airstrikes.
The first strike in the early dawn hours killed 21-year-old Osama Bahjat Rajat and 23-year-old Muhammad Dwood Hamoudah. The second strike was around 8 a.m. and it killed two people in al-Shayma neighborhood of Beit Lahiya.
Mujahid Skafi, a young man from the Tuffah neighborhood of Gaza City died Wednesday morning of wounds he sustained during artillery shelling Tuesday.
Israeli warplanes struck on Wednesday morning home of Hamas' leader Nizar Awadallah in al-Shati refugee camp in the northern Gaza Strip for the second time.
A mosque known as Omar Ibn Abd al-Aziz Mosque in Beit Hanoun in northern Gaza was also hit Wednesday morning as well as a house belonging to al-Masri family in Beit Lahiya.
The home of a leader in the Democratic Front for the Liberation of Palestine Ziad Jarkhoun was also targeted in Rafah in the southern Gaza Strip.
AFP contributed to this report.