Israeli soldiers stand on top of their tanks and armoured personnel carriers (APCs) across from the northern Gaza Strip. REUTERS/ Baz Ratner

Gaza City, Palestinian - Thirty-nine Gazans were killed on Friday as Israel pressed a major ground offensive in the coastal enclave, raising the overall Palestinian death toll since July 8 to 280, medics said.

An Israeli soldier was also killed as troops began an offensive on the Gaza periphery aimed at destroying Hamas's network of cross-border tunnels, the army said.

The latest deaths included four children killed in tank shelling east of Gaza City, ranging in age from two to 13-years-old, emergency services spokesman Ashraf al-Qudra said.

Among them were brothers Emad Alwan, seven, and Qasem Alwan, four.

In the southern city of Rafah meanwhile, a man was killed by tank shelling, and in Khan Yunis, a 23-year-old died of wounds sustained earlier in the week.

The deaths raised the toll in Gaza during the 11 days of the conflict to 280, as Israel pressed a ground operation it announced on Thursday night.

Earlier, three people were killed in Khan Yunis in the south, one man killed in Nusseirat in central Gaza and another death was reported in a cemetery in the northern Gaza Strip, Qudra said.

Elsewhere, medics found the bodies of another four people: two of them just to the east of the southern city of Rafah, and another two in Khan Yunis, one of them a 17-year-old, he said.

Another eight people had earlier been killed in and around the northern town of Beit Hanun, among them three teenagers.

And in the southern city of Khan Yunis, six people from two families were killed, as well as another three who were killed by tank fire.

Attacks in Rafah, which straddles the border with Egypt, claimed five lives in several different attacks, among them a five-month-old baby.

To the east of Gaza City, another person was killed in Shejaiya, and medics also found the body of a man killed in a strike south of the city.

Figures provided by the Gaza-based Palestinian Centre for Human Rights show civilians account for more than 80 percent of the victims of Israel's assault since July 8 to halt rocket fire by militants of the Islamist movement Hamas which controls the coastal strip.

At least 1,920 Palestinians have also been wounded.

Since the Israeli operation began, more than 1 207 rockets fired from Gaza have struck Israel, and another 333 have been shot down by the country's Iron Dome air defence system, army figures show.

On the Israeli side, a civilian was killed by rocket fire earlier this week, and a soldier was killed overnight in Gaza. Four Israelis have been seriously injured.