Palestinian health officials say three Palestinians have been killed in an Israeli missile strike in the northern Gaza Strip.

Sources say the three people killed in Saturday's attack near the town of Beit Hanoun were employees of a bank.

The Israeli military confirmed the missile strike and said it targeted Palestinian militants preparing to launch mortar shells into Israel.

Meanwhile, merchants in the Gaza Strip closed their shops today to protest Israel's blockade of the Palestinian territory.

Israel closed its border crossings with Gaza after Hamas militants took control of the territory last June, and has been restricting fuel and electricity deliveries to Gaza to pressure militants into stopping constant rocket attacks on Israeli towns.

Gaza is home to 1.5 million Palestinians who depend heavily on outside aid.

In the West Bank, Israeli forces arrested a militant leader during a raid in a refugee camp near the city of Nablus. The militant is from the Popular Front for the Liberation of Palestine, a radical Palestinian faction.

In other news, Palestinian President Mahmoud Abbas has opened an investigation into the death of a Hamas preacher whom the Islamist group said was tortured by Fatah security services.

Majed Barghouti died Friday in the West Bank city of Ramallah, a week after being detained by Fatah security personnel.

Hamas denounced the death as a crime. Fatah, led by Mr. Abbas, and Hamas are rival Palestinian factions.

Some information for this story provided by AP, AFP and Reuters.