An Israeli border policeman was shot to death and another wounded by Arab gunmen today in the center of the West Bank city of Nablus.

The killing bore striking similarities to a wave of hit-and-run attacks on Israeli soldiers and civilians last summer in crowded markets of Arab towns and cities. The attacks led to a security clampdown in the occupied territory.

Today's shootings also underscored the danger to increasing numbers of Israelis who regularly visit West Bank Arab markets on Saturdays looking for bargains.

The Israeli Army command said tonight that Cpl. Jamil Sares, 46, a Druze member of the paramilitary border police since 1967, was gunned down outside a clothing store in Nablus' main commercial street while shopping with his wife and children.

Sares, who was off duty but in uniform and carrying a weapon, was shot as he ran out of the store after another border policeman was shot while walking a beat on the street just outside the shop. The second policeman, who was not identified, was taken to a Tel Aviv hospital.

An Army spokesman said that four Arab passers-by were wounded in the gunfire. They said that neither of the policemen had a chance to fire back at their attackers, who disappeared in the crowd.

A round-the-clock curfew was imposed on Nablus, as Army patrols began conducting house-to-house searches. Authorities said a number of Arabs were arrested for questioning.

The newly appointed mayor of Nablus, Zafir Masri, immediately issued a statement condemning the attack. Masri, who supports the Palestine Liberation Organization but is considered moderate by Israeli officials, was named last month by the military governor of the West Bank to take over from the Israeli Army administration that had governed Nablus since the Municipal Council was disbanded in 1981 following civil unrest.

An Army command spokesman said the attack appeared to be "well organized," and that one of the two gunmen shot the on-duty border policeman while the other waited for Sares to run out of the shop.

Following a spate of similar hit-and-run attacks on Israelis in the West Bank late last summer, the West Bank military government urged Saturday shoppers not to enter Arab markets unarmed.