Four Palestinians were wounded on Wednesday when an unexploded ordnance went off in eastern Gaza City, medical sources and witnesses said.

Medical sources said four young men sustained moderate and serious injuries with one of them losing his leg.

Witnesses confirmed that the explosion occurred in an open area near al-Zaytoun, a residential area that Israel targeted at the beginning of its ground invasion into Gaza on January 5, 2009.

They added that the explosive object was an artillery shell.

During the Israeli offensive on Gaza, Israel showered the Gaza Strip with tens of 155 mm artillery shells, and some of them were said to be laden with white phosphorus. Most of the artillery shells landed in border areas and the outskirts of the Palestinian communities.

More than 1,300 Palestinians were killed in the 22-day offensive which first started with airstrikes on December 27, 2008.