JERUSALEM — Security measures throughout the country have been tightened since Monday's pipe-bomb blast in the heart of Hadera, in which 25 people were slightly wounded.

The manner of the attack, including the type of device used and where it was planted to cause maximum casualties, was similar to recent terror bombings in Netanya.

Three times over the past months, pipe bombs hidden in trash cans and bags were used by terrorists in attacks in Netanya, where 33 people were wounded in a bombing attack last November.

Security forces are investigating a possible connection between the bombings, as well as the possibility they were the work of a single terrorist cell possibly affiliated with Islamic Jihad. Security officials believe three cells operating in the Hebron area and several others in the West Bank are responsible for the string of attacks.

Channel 2 reported this week of general warnings that terrorist organizations would try to carry out more attacks to torpedo the peace process.

According to the report, senior police officers met Monday night. They recommended beefing up checkpoints at the entrances to large towns and cities and adding more police and border police on the streets. Police called on the public to remain alert and not hesitate to report suspicious looking objects or people to the authorities.

Deputy Defense Minister Ephraim Sneh said the Hadera attack was definitely a terrorist bombing and that the perpetrators came from the West Bank.

"The terrorist cells are making efforts, within the confines of their operational capabilities, to confound the atmosphere, cause casualties and try to create an environment which is hostile to peace," Sneh said.

The bombing in Hadera, which is about halfway between Tel Aviv and Haifa, occurred around 11 a.m. in a square among several banks, commercial centers and the market.

The homemade device had apparently been planted between benches that would normally have been packed with mainly elderly people enjoying the winter sunshine. On Monday, however, there were fewer people than usual at that hour and those who were caught in the blast were saved from serious injury by a garbage can close to the device, which absorbed most of the blast.

Even so, 25 people were either wounded by fragments or nails from the bomb itself or other debris hurled through the air by the explosion, or had to be treated for shock.

"I was sitting on the bench, talking…Suddenly, there was an explosion underneath us. I was thrown onto my friend and then we got away from there," Meir Abu, an elderly Hadera resident, told reporters at the scene.

The victims were all taken to nearby Hillel Yoffe Hospital, where most were released after treatment, although eight were kept for observation, including one person who suffered complications as a result of the blast.

Police detained and questioned a number of Palestinians from the territories in the area, but there were no reports of any arrests. Security sources noted that it was not the first attack in Hadera and that terrorist groups had previously taken advantage of the fact that many people from the territories go to the city looking for work.

"We will take action to crush the terror. And I am confident that whether sooner or later, we will find and punish the perpetrators of this attack," Prime Minister Ehud Barak said.

"We will get our hands in due time on the terrorists who carried out this painful attack."

A top Palestinian official condemned the attack.

"Our position is clear, we do not condone such acts," Palestinian negotiator Saeb Erakat said.