An Israeli general told parliament that Palestinian terrorists planned to release cyanide gas to enhance the killing power of a recent suicide bombing, an army spokesman said Wednesday. Israeli experts said it was one of several attempts focused on causing large numbers of casualties.

The bombing — at a Passover dinner March 27 in the seaside city of Netanya — was the deadliest during 20 months of Israeli-Palestinian fighting. It killed 29 Israelis and set off Israel's six-week military offensive in the West Bank.

But according to Maj. Gen. Aharon Zeevi, the Israeli chief of military intelligence, it was meant to be much worse.

Zeevi told parliament's security committee Tuesday that the bomber was supposed to release cyanide gas, but did not because of a technical mishap, said the spokesman, Brig. Gen. Ron Kitrey.

"We are talking about an intention," Kitrey said Wednesday. He would not give further details.

Cyanide gas can be fatal in an enclosed space, such as the dining hall where the Netanya attack took place.

The allegation came the same day a suicide car bomber drove alongside an Israeli bus, setting off an explosion that killed 16 passengers.

Another attack that Israeli security experts said could have killed thousands came last month when a bomb went off under a tanker truck just after it entered Israel's main fuel depot, situated in the country's most populous region, the Tel Aviv metropolitan area.

The fire was put out and no one was hurt, but officials said that if the huge above-ground natural gas tanks had exploded, death and destruction would have swept over part of the Tel Aviv area, where about a third of Israel's 6 million people live.

After the failed May 26 attack at the Pi Glilot fuel depot, newspapers printed maps with concentric circles representing the extent of potential damage in the crowded urban areas, and experts pondered how far Israel would go in military retaliation for a terror strike on such a scale, citing scenarios like conquering the West Bank and Gaza Strip and expelling the Palestinian leadership.

Palestinian leader Yasser Arafat and the Palestinian Authority have denounced terror attacks against Israeli civilians.

Israeli security officials say they also discovered a plot last month to bomb the Azrieli Center in downtown Tel Aviv. The twin towers — the Israeli version of the World Trade Center — are 50 and 46 stories respectively.

On Tuesday, using another high-rise in Tel Aviv, Israeli police and rescue services drilled procedures for dealing with an attack like in New York on Sept. 11.

Zeev Schiff, a military commentator for the Haaretz daily, said Palestinian militants groups were constantly looking for ways to carry out large-scale attacks.

Barry Rubin of the BESA center for strategic studies at Bar Ilan University said Palestinian terrorists "stage every attack that they're capable of."

However, he said, the Palestinian groups "don't have the means" to carry out large-scale attacks and doubted whether such missions were a high priority.

"The main goal is large numbers of attacks on Israel, on a continuing basis, as part of a war of attrition to wear Israel down," Rubin said.

Israeli counterterrorism expert Reuven Paz noted that Islamic attacks by Islamic groups, like the one that claimed responsibility for Wednesday's bombing, involved what was viewed in the Muslim world as personal sacrifice and heroism.

For example, that there had been no known attempts to poison Israel's water supply, "where there is no personal touch," he said.

"For the time being this is their reality," Paz added. "It might change."