JERUSALEM — Irate Israeli reservists demanded a formal inquiry yesterday into the Lebanon war as returning combatants recounted stories of shocking military incompetence.

One group spoke of how they were sent to war in the choking summer heat without water.

They had to grab canteens from the bodies of Hezbollah fighters. They staged protests in several ways.

Some signed a petition; others pitched tents outside government buildings in Jerusalem. But their message was clear.

They charged that Prime Minister Olmert and his security advisers provided dithering and incoherent leadership and must be held to account.

Many of the protesters simply called for the security elite to resign. The military is a potent constituency in a country that regards its soldiers with almost sacred respect.

Hundreds of members of the Spearhead Brigade, a reserve unit that fought in south Lebanon during the month-long conflict, signed a petition published in a newspaper that attacked the “cold feet” of their commanders.

“There was one thing we were not and would not be willing to accept,” the petition said. “We were unwilling to accept indecisiveness. The war’s aim, which was not defined clearly, was even changed in the course of the fighting.

“The indecisiveness manifested itself in inaction, in not carrying out operational plans, and in canceling all the missions we were given during the fighting.

“This led to prolonged stays in hostile territory without an operational purpose.”

In scenes reminiscent of the first demonstrations that ultimately toppled Israel’s leaders after blunders in the 1973 Middle East war, about 100 people, many of them reservists, marched in Jerusalem.

They set up a protest tent in a park near the government office compound.

“The government didn’t take seriously the lives of our troops,” a reserve infantry soldier, Zvi Marek, said.

Another march was held near Jerusalem in honor of an Israeli soldier killed in the war, Rafanel Muskal.

It was led by his father, Moshe, who did not hide his contempt for Mr. Olmert’s leadership.

“Many parents who lost their sons in the war will join us,” he said. “Olmert is being asked to go home without any commissions of inquiry and no p.r. spins.

“This demand is taking on a wide scope, and it appears the entire nation is with us.”

The reservists provide the backbone of the army in wartime. Afterward, they return to their civilian lives and are able to vent their anger.

The sense of muddle in the Israeli leadership over the war is reflected in the plethora of inquiries being prepared by various government departments.

The state ombudsman announced yesterday that he would be holding his own investigation, along with one already announced by the defense ministry.

Mr. Olmert is on the verge of announcing yet another, even higher-level inquiry, although the debate over its terms of reference and powers of subpoena continues.