Gaza - Israeli troops killed four Palestinians in a fire- fight in the southern Gaza Strip Wednesday, further battering an already shaky truce.

An Israeli military spokeswoman in Tel Aviv said the troops had spotted a group of armed men making their way to the border fence which separates the salient from Israel, and had opened fire.

Palestinian witnesses and police officials said the Israelis had entered the Strip, this sparking the clash with militants positioned near the border fence. During the fighting mortars were also fired at the Israeli forces.

The ceasefire which came into effect on June 19 was severely tested last week when Israel destroyed a tunnel bring dug under the border, in order, it said, to facilitate the kidnapping of Israeli soldiers.

Five militants and a civilian woman died in the Israeli action, which prompted the militants to resume rocket barrages on southern Tel Aviv, after months in which single missiles had only been fired sporadically. (dpa)