JERUSALEM — Two Israeli police officers were shot dead in their patrol car in the Jordan Valley area of the West Bank on Sunday night, police officials said. Although the identities of the gunmen were not immediately clear, Israeli security officials said they were treating the killings as a probable nationalist attack by Palestinians.

The attack, along the Jordanian border near the Jewish farming settlement of Massua, came as Israel began easing travel restrictions for Palestinians around Nablus, a Palestinian city northwest of the settlement.

Earlier Sunday, the Israeli military opened the Beit Iba checkpoint, northwest of Nablus, for the first time in eight years. Dozens of checkpoints were erected throughout the West Bank after the outbreak of the second Palestinian intifada in 2000.

The military said in a statement that the Beit Iba crossing was being dismantled as part of “good-will measures authorized by the minister of defense, and as a result of the significant decrease in terror attacks originating from Nablus.”

A Jewish settlers’ committee in the northern West Bank said the deaths on Sunday were “the direct result of the reckless removal of roadblocks.”