An explosive charge blasted shrapnel into elderly people sitting on a park bench and shoppers on the sidewalk in this coastal Israeli city today, injuring 22. Authorities cast a wide net of possible blame, naming Palestinian groups that reject the peace talks between Israel and the Palestinians.

But the Israeli government is looking for reasons to go ahead with the talks, not reasons to stop them. Prime Minister Ehud Barak said tension over the peace talks means that Israel has entered "critical months" and warned there would be other attacks. Even so, he said he would press ahead with the quest for a peace accord.

Barak and Palestinian leader Yasser Arafat held a secret meeting a few hours after the attack. Israel Radio reported that Barak was asking Arafat for a two-month delay in reaching a framework agreement for a final peace treaty. Barak's office would not confirm the report, but his chief negotiator voiced doubt Sunday that the Feb. 13 deadline would be met.

A senior Palestinian official, Nabil Shaath, denounced the attack. Israeli intelligence officials have said they believe the Palestinian Authority, led by Arafat, has done much to eliminate terror groups in the areas under his control in the Gaza Strip and the West Bank.

Deputy Defense Minister Ephraim Sneh said today that Iran is helping radical Palestinian groups carry out such attacks because it shares their goal of disrupting the talks. But, he said, "Our intention is not to allow such attacks to derail the peace process."

Police said today's explosive device at Hadera, about 25 miles north of Tel Aviv, was similar to one set off in Netanya last November, when at least 14 people were injured.

People on Rothschild Street, where the bomb went off, swiftly returned to business today, strolling and buying from outdoor market stalls. As Rimon Hadad, 57, watched police collect explosive residue from the trash can where the bomb was placed, he talked about what he said was Israel's search for peace and pointed to the monument to Israelis who drained the swamps around Hadera many years ago.

"This doesn't matter," he said. "We have to go on."

Police cleared central Hadera for two hours as they looked for more hidden explosives. Nothing was found. As soon as they signaled all clear, people flowed back, stepping over blood stains on the red brick sidewalk and trails of blood on the street left by the injured as they ran from the explosion.