GAZA, Oct 31 (Reuters) - An Egyptian-brokered truce appeared to be taking hold on Monday to end a five-day flare-up in violence between Israel and militants in the Gaza Strip in which a dozen Palestinian gunmen and an Israeli civilian were killed.

The border was largely quiet since midnight when Israel, saying it had targeted a rocket-firing squad, killed two militants with an air strike in southern Gaza.

As it seems, this (round of violence) appears to be behind us, Israeli Home Front Security Minister Matan Vilnai said on Army Radio.

Most of the rocket firing from Gaza was carried out by the Islamic Jihad group, which suffered the most casualties, while the territory's Hamas rulers held their fire. Islamic Jihad has close ties with Iran and has chafed at the rule of rival Hamas.

The violence began when residents of Israeli suburbs south of Tel Aviv were jolted awake on Wednesday night by sirens usually sounded in towns and villages closer to the Gaza Strip.

The alert was triggered by what Israeli security sources said was an upgraded long-range Grad rocket that struck harmlessly near the Israeli port city of Ashdod.

Israel launched an air strike on Saturday that killed five top Islamic Jihad militants in a Gaza training camp.

One of some 30 rockets and mortar bombs fired at Israel killed an Israeli man in the city of Ashkelon. Two other people were wounded.

Egypt officials said they were able to get both sides to agree to a ceasefire.

The violence erupted after weeks of a relative lull surrounding a prisoner swap on Oct. 18 in which Israel released 477 Palestinian prisoners in exchange for Gilad Shalit, an Israeli soldier held by Hamas since 2006. (Reporting by Nidal al-Mughrabi; Editing by Ralph Gowling)