Israeli tank shells killed at least four Palestinians and wounded 25 in the Gaza Strip on Saturday after an apparent attack on an Israeli army patrol in the border area, Palestinian medics and local witnesses said.
The casualty toll was one of the highest in a single incident in Gaza in recent months. Residents said a crowded mourning tent in the Shijaia neighbourhood near Gaza City was full of people paying respects to a bereaved family man when a shell struck.
Ambulances, private vehicles and motorbikes rushed the wounded to hospital, eyewitnesses said. Among those killed was an 18-year-old man.
"The occupation's targeting of civilians was a grave escalation that must not pass in silence," said Hamas spokesman Fawzi Barhoum. "Resistance must be reinforced in order to block the aggression."
The Israeli military declined immediate comment, but Israeli media reported that an army patrol car was hit and badly damaged by an anti-tank missile east of Gaza City shortly before the strike on Shijaia.
In an separate incident at another location, four people were wounded in an Israeli air strike in the town of Khan Younis.
The attack took place during a period of increased tension along the Israel-Gaza frontier.
In an attack on Thursday, a Gaza boy was killed by Israeli gunfire as troops fought a gun battle with Palestinian militants. Shortly afterwards, militants blew up a tunnel packed with explosives near the border.
The Gaza Strip, a coastal territory crowded with more than 1.5 million people, many of them refugees, is controlled by Hamas Islamists who reject Israel's right to exist.