RAMALLAH, West Bank ? Israeli troops chasing militants in the West Bank surrounded homes, a hospital and a downtown square Thursday, killing five armed Palestinians and two bystanders, while soldiers reoccupied Bethlehem after withdrawing over Christmas.

The military activity reflected Israel’s strategy of seizing the initiative in its conflict with the Palestinians instead of reacting to Palestinian attacks.

But the largest Palestinian death toll in weeks also raised concerns of new efforts by Palestinian militants — who have not staged a major terrorist attack in almost a month — to retaliate.

An escalation of the 27-month conflict also could affect Israel’s Jan. 28 election. Prime Minister Ariel Sharon’s Likud is ahead in the polls, but his advantage has been slipping because of a police investigation of alleged vote-buying in recent internal party elections.

In Bethlehem, Israeli forces imposed a curfew again, confining residents to their homes until further notice. The curfews usually are enforced around the clock except for periodic breaks of a few hours to allow people to buy food. On Christmas Eve, the Israelis had pulled back from the center of town.

On Thursday, Israeli jeeps drove back through the town, residents said. Soldiers with loudspeakers declared the curfew and threw tear gas canisters at people celebrating the Christmas holidays, forcing them indoors. The Israeli military said the curfew was brought back for security reasons.

Israel’s latest occupation of Bethlehem came after a Palestinian suicide bomber from the town blew himself up on a bus Nov. 21 in Jerusalem, killing 11 passengers. Israel says it had received warnings of other militants planning attacks originating in Bethlehem.

In clashes Thursday, Israeli soldiers killed five armed Palestinian fugitives and two bystanders — a teenager and a traffic policeman.

A Palestinian man tries to persuade an Israeli soldier to allow him to enter the Israeli-controlled sector of Hebron to reach his house. The soldier denied the man access Thursday, saying the area was under military curfew. Israeli officials said the curfew was brought back for security purposes.

In Ramallah, soldiers surrounded a hospital and fired at the guard room, killing an armed guard and arresting three others, Ramallah governor Mustafa Issa said. The military said soldiers shot a wanted Palestinian who tried to escape.

Also in Ramallah, where Palestinian leader Yasser Arafat has his headquarters, soldiers in plain clothes tried to arrest a wanted Palestinian, but he ran, so soldiers shot and killed him, the military said. Then Palestinians threw rocks at the soldiers, who opened fire, killing a 19-year-old traffic policeman, Palestinians said.

In Tulkarem, Israeli soldiers killed a local leader of the Al Aqsa Martyrs’ Brigades, a militia linked to Arafat’s Fatah movement. The military said he tried to escape.

In Nablus, soldiers searching for a fugitive killed a Palestinian gunman in an exchange of fire, the military said.