Thousands of Israelis continued to queue up for gas masks or ordered them by phone, spurred on by fears that any Western military response to last week's alleged chemical weapons attack in Syria could ensnare their own country in war. (NIR ELIAS/Reuters)

A shortage of gas masks caused a mini-melee among panicky moms pushing strollers here Wednesday, as Israelis prepared for possible U.S. airstrikes against Syria that could trigger retaliatory attacks in Israel.

At a post office distribution center in the Hadar Mall in West Jerusalem, Israelis broke through yellow security tape and clawed into boxes containing the government-issued kits. Postal authority spokeswoman Maya ­Avishai described the scene as “a brutal onslaught” against law and order, and police were called to calm the crowd.

Jamie Schwed, mother of a newborn, was frustrated to find that all the gas masks had been distributed. “They warned us of a possible attack, and they run out of masks? It’s ridiculous,” she said.

Officials reported a surge in inquiries, deliveries and people lining up for the free kits, as the United States and its Western allies gathered support for a strike on Syria in retaliation for last week’s alleged poison gas attack outside Damascus. The Syrian government denies responsibility for the attack, which killed hundreds, including many women and children.

A U.N. weapons team is inspecting the sites, searching for definitive proof that banned chemicals were used. But the United States and its allies say information provided by intelligence services has convinced them that the government of President Bashar al-Assad used chemical weapons.

The Israeli government is walking a fine line, encouraging citizens to be prepared for the possibility of retaliation from Syria if it is attacked but also telling them not to panic. “There is no reason to change daily routines,” Prime Minister Benjamin Netanyahu said. “At the same time, we are prepared for any scenario.”

The Israeli military ordered reserve troops to muster at the northern border.

About 60 percent of Israel’s 7.7 million citizens have gas masks. Chilik Soffer, former head of the military’s Home Front Command, said it would take up to two years to supply the entire population with masks. In parliament Wednesday, the opposition blasted Netanyahu’s coalition government for the shortfall.

“Against a conventional attack, we’re ready. Israel is very, very ready,” Soffer said. “But against an unconventional attack? I am not so sure.”

Israelis with long memories recalled the 1991 Persian Gulf War, when then-Iraqi President Saddam Hussein bombarded the Jewish state with Scud missiles, and citizens huddled in “safe rooms,” hoping that sheets of plastic and masking tape would protect them from threatened chemical or biological attacks.

At Washington’s urging, to keep the international coalition against Hussein intact, Israel did not respond to the Scud attacks. But Netanyahu and his generals have made clear that they have no intention of standing down if attacked by Syria or Hezbollah, the Lebanon-based Shiite Muslim militant group backed by Iran.

“Those seeking to strike us will find us sharper and fiercer than ever,” said Lt. Gen. Benny Gantz, Israel’s top military commander. “Our enemies must know we are determined to take any action needed to defend our citizens.”

According to Israeli officials and retired officers who serve as military analysts here, the consensus in the country’s intelligence community is that Syria will not strike against Israel in retaliation for a U.S. cruise-missile attack.

Israeli warplanes are said to have bombed Syria twice this year, in January and May, apparently in an attempt to stop the transfer of weapons from Syria to Hezbollah outposts in Lebanon. Neither attack provoked a response from Syria.

Still, some Iranian lawmakers warned Wednesday that a U.S. attack on Syria would be met by an attack on Israel. And as tensions rose, Israeli citizens acknowledged feeling uneasy.

“What we hear is that there will be an attack on Syria in the next two days, and it could affect us,” said Daoud Sayad of East Jerusalem, who came to collect his mask with five members of his family. “I don’t know where to go or what to do now.”

Talia Kaufman, who has lived in Israel for the past four years, said she did not get a gas mask during past threats but was determined to do so this time, as the mother of a 9-week-old. “I am definitely concerned,” Kaufman said, “because this time, we know chemical weapons are involved.”

Israeli officials ratcheted up their rhetoric, declaring bluntly that Assad had gassed his people and should be punished.

“It takes a barbarian to employ poison gas,” tweeted Lt. Col. Peter Lerner, a spokesman for the Israel Defense Forces, who likened Assad to Mussolini, Hitler and Hussein. Defense Minister Moshe Yaalon called the Assad government “monstrous.”

Yuval Steinitz, Israel’s minister for international affairs, strategy and intelligence, said it is “crystal clear” that the Syrian military launched last week’s attack and that it involved chemical weapons.

“The world cannot allow this to continue,” Steinitz said. Syrian leaders, he added, “have no barriers, no moral inhibitions.”