Israeli tanks have raided the eastern suburbs of Gaza City, leading to one of the deadliest days of violence in recent months.
At least 18 Palestinians died and dozens more were wounded during the clashes. Most of those hit appear to have been militants, but others were civilian bystanders.
Several Palestinians were arrested in raids said to be aimed at preventing rocket fire from Gaza, which has been controlled by the Islamist militant group Hamas since June.
In a day of violence on both sides of the Gaza border, a labourer from Ecuador working on an Israeli kibbutz was killed by sniper fire claimed by Hamas.
The Israeli town of Sderot, just a few hundred metres from Gaza, was also hit by indirect militant fire, wounding a number of residents.
One of those killed in Gaza was a son of Mahmoud Zahhar (right), a senior leader of Hamas, seen here arriving at a hospital morgue to see the body.
At the same Gaza City hospital, Hamas leader Ismail Haniya donated blood.
The dead were given "martyrs' funerals" at the Omari mosque in Gaza City, with hundreds of mourners taking part.
Palestinian relatives of the dead and Hamas vowed revenge. The rival Palestinian Fatah movement condemned what it called a "massacre", hampering its peace talks with Israel.