JERUSALEM — The call came to the cellphone of his brother’s wife, Salah Kaware said Tuesday. Kaware lives in Khan Younis, in southeast Gaza, and the caller said that everyone in the house must leave within five minutes, because it was going to be bombed.

A further warning came as the occupants were leaving, he said in a telephone interview, when an Israeli drone apparently fired a flare at the roof of the three-story home.

“Our neighbors came in to form a human shield,” he said, with some even going to the roof to try to prevent a bombing. Others were in the stairway when the house was bombed not long afterward.

Seven people died, Kaware said, a figure also stated by the Palestinian Health Ministry in Gaza, which also said that 25 people were wounded.

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The Israeli military said that targeted houses belonged to Hamas members involved in launching rockets or other military activity, and that they had been used as operations rooms.

But the events on Tuesday were another example of a contentious Israeli policy in which occupants of a building about to be bombed or shelled are given a brief warning in Arabic to evacuate.

The Israelis have used such telephone calls and leaflets for years now, in a stated effort to reduce civilian casualties and avoid charges of indiscriminate killings or even of crimes against the rules of war.

During Operation Cast Lead in Gaza in late 2008, the Israelis often used telephone calls and leaflets to tell occupants to leave before striking. In some cases, the Israelis fired missiles without explosive warheads onto the roof to get Palestinians who had gathered there to leave.

The Israelis called it “the knock on the roof.”

But often, as in Khan Younis on Tuesday, people die in any case, because they ignore or defy the warnings, or try to leave after it’s too late.

And, of course, sometimes bombs and missiles do not hit the building at which they’re aimed.

The Israelis also regularly drop leaflets over Gaza urging citizens to not cooperate with terrorism and to stay away from border zones, an injunction that has been criticized by human-rights advocates, like the Palestinian Al Haq organization, which argue that such leaflets do not protect Israel from allegations of the indiscriminate killing of civilians.

Groups such as Human Rights Watch have regularly said that Israel’s efforts to warn civilians with phone calls and leaflets do not absolve the armed forces, which “still need to ensure that the warnings are effective and do not allow attacks otherwise prohibited under international law,” the group said in 2009, even as it welcomed “new procedures to improve its early warning to civilians during armed conflict.”

Israel also uses leaflets in Arabic, some of them intended as warnings and others as propaganda.

On Tuesday, many were dropped over northern Gaza near Israel.

One said that “the terrorist elements, tunnel owners and arms smugglers know very well that the continuation of the terror operations, the smuggling of arms and the digging of tunnels constitute a lasting target for the operations of the Israel Defense Forces.”

“However,” it said, “they continue working from the areas you live in and take you as cover.”

The leaflet urged residents not to allow their houses to be used as covers for digging tunnels or smuggling weapons, and provided an email address and phone number for people to report on such activities around them, saying, “Don’t stand idle as the terrorist elements use you.”

Israel does not always give warnings, of course. Also Tuesday, a missile hit a car traveling along a central Gaza thoroughfare, killing the three occupants. It was not immediately clear who the targets were, though one was reportedly a senior Hamas military official, Muhammad Shaban, and it seemed unlikely anyone had called them to forewarn that a missile was on the way.