Israeli missiles target and kill Hamas leaders

Four members of the militant Islamic group Hamas were killed today in an Israeli missile attack on cars in the Gaza strip.

The Israeli military said it targeted and killed Yasser Rizik, a ‘‘senior Hamas activist’’ who was behind a January attack that killed four soldiers.

Six people died in two cars that were hit by missiles fired from helicopters and five were injured.

Later, Palestinian police surrounded the house of Hamas spiritual leader Sheik Ahmed Yassin in Gaza and placed him under house arrest. About 40 Hamas supporters threw stones and bottles at the police, who fired into the air to quell the crowd.

In the West Bank, Israeli tanks once again encircled Palestinian leader Yasser Arafat’s badly damaged headquarters and barricaded the front gate with debris as the army seized control of Ramallah.

Israeli soldiers on top of armoured personnel carriers flashed V-for-victory signs as dozens of tanks and vehicles rolled into the town under the cover of two helicopters.

The troops took up positions around Arafat’s offices, where a bulldozer quickly began fortifying barriers at the front gate. More than 20 tanks were parked on the street that surrounds Arafat’s compound by the afternoon.

Israel forces have besieged Arafat’s compound on and off since last December, and today’s action marked the third time this month to troops have surrounded his offices, which now consist of many battered and scorched buildings that cover a full city block.

‘‘The Israeli government, with these continuous attacks, has revealed to the whole world its real intentions,’’ Arafat said.

‘‘Nothing can weaken our belief in our legal right to have our own independence and freedom, and all this Israeli aggression will not achieve any political results.’’