JERUSALEM — Prime Minister Olmert and Defense Minister Amir Peretz came under renewed pressure to resign yesterday after the Israeli army’s chief of staff stepped down in the wake of criticism regarding the Lebanon war.

The sudden departure of Israel’s top military official, Lieutenant General Dan Halutz, delivered another setback to the prime minister, whose popularity has plummeted following last summer’s war and a string of political scandals. On Tuesday, Israel’s attorney general opened a criminal probe into Mr. Olmert’s role in a 2005 bank privatization.

General Halutz stepped down after dozens of internal inquiries into the month-long Lebanon war found widespread problems in the military’s performance. General Halutz had previously rejected calls to resign, despite the growing loss of confidence of his political superiors and subordinates in the army.

With General Halutz on his way out, critics quickly clamored for the heads of the country’s other wartime leaders, Messrs. Olmert and Peretz.

“The war clearly was mismanaged, and when a war is clearly mismanaged, there is no doubt the chief of staff is responsible,” said opposition lawmaker Ran Cohen, a former high-ranking military officer. “The responsibility is shared by him, the prime minister and the defense minister, and sooner or later, they, too, will have to leave.” Mr. Peretz expressed regret General Halutz’s decision, but he warned Israel’s enemies not to misinterpret the move.

Speaking at the graduation ceremony for naval commanders in Haifa, Mr. Peretz said General Halutz’s decision was “premature.” “I am sorry he won’t be with us to complete the task” of restoring the army after the failures of the summer’s war in Lebanon, Mr. Peretz said.

Mr. Peretz, who is also under fire about the war, had a message for Israel’s enemies. “Do not misinterpret the army chief’s decision to resign as a sign of weakness,” he said. Mr. Olmert made a routine appearance at parliament, sparring with lawmakers over unrelated domestic issues and promising to appoint a new military chief within days. Mr. Peretz said he would begin interviewing candidates for the vacant military post immediately.

But pressure on Messrs. Olmert and Peretz is likely to increase ahead of the release of a wide-ranging government inquiry into the war. The investigative panel, focusing on the performance of military and political leaders, is expected to announce its conclusions in the coming weeks.

“General Halutz’s step was unavoidable, but he was not the only one responsible for the failures of the war — the government was too,” lawmaker Ophir Pines-Paz, a member of Mr. Peretz’s Labor Party, told Army Radio.

He stopped short of calling on Messrs. Olmert and Peretz to resign, saying he wanted to wait for the government panel to reach its conclusions.

An opinion poll published last week showed Mr. Olmert’s approval rating at just 14%, and his Kadima Party losing if new elections were held.

“It is not clear whether the prime minister will be able to survive the resignation of chief of staff General Halutz and his own political problems,” said Ephraim Inbar, a political scientist at Bar-Ilan University near Tel Aviv. “We may see pressure in his own party to replace him. This resignation is definitely the beginning of political turmoil in Israel.”

Mr. Peretz’s public standing, meanwhile, is equally dismal. The former union leader won the defense portfolio under a coalition deal with Mr. Olmert’s Kadima Party, despite his scant military experience.

The war’s many flaws only cemented sweeping doubts about his fitness to serve as defense minister, and he now faces multiple challenges to his leadership within his own Labor Party, which is scheduled to hold primaries for chairman in May.

Both Messrs. Peretz and Olmert “are in a very shaky position,” said political scientist Avraham Diskin of the Hebrew University in Jerusalem.

Israel went into the war with a united front against Lebanese Hezbollah guerrillas just hours after they killed three Israeli soldiers and captured two in a July 12 cross-border raid, but that solidarity collapsed after the fighting ended.