TEL AVIV — Israeli tanks shelled the Gaza Strip, killing at least three Palestinian-Arabs, after Hamas terrorists fired some 20 mortars at Israel, the head of Palestinian-Arab emergency services in Gaza and the Israeli army said.

The shelling came as Prime Minister Olmert of Israel conducted a formal assessment yesterday with the Defense minister, Ehud Barak, and the Foreign minister, Tzipi Livni, on a proposed expansion of military action in Gaza to stop Palestinian-Arab rocket firings.

The two events were not connected, an Olmert spokesman, Mark Regev, said. “It’s a very complex situation,” Mr. Regev said by telephone. “I wouldn’t read anything into” the timing.

Mr. Olmert said upon returning from Washington last week that the “pendulum is much closer to tough military action” after an Israeli worker was killed in a mortar attack by Hamas. At the same time, Israel is still considering an informal truce with Hamas that is being promoted by Egypt.

In yesterday’s shelling, the army fired after members of Hamas lobbed 20 mortar shells into Israel during the morning, according to an Israel Defense Forces spokeswoman who couldn’t be identified under military regulations.

Three Palestinian-Arabs were killed and five were wounded by the Israeli shells that were fired at the eastern Sheja’eya neighborhood in Gaza City, the chief of emergency services in the Palestinian Health Ministry, Mo’aweya Hassanein, said.

Before starting the Gaza deliberations Mr. Olmert told his Cabinet he was pleased at the level of strategic coordination he achieved during talks in Washington last week with President Bush, Vice President Cheney, Secretary of State Rice, and senior members of the National Security Council.