At least eight Palestinians, including four civilians, were killed yesterday during heavy exchanges of fire between the Israel Defense Forces and Palestinian terror groups in the Gaza Strip, in one of the most serious rounds of fighting near the Strip since the end of Operation Cast Lead in January 2009.

Senior IDF officers said yesterday that neither side is interested in escalation. However, Hamas and the other armed Palestinian factions appear to be trying to hit IDF forces patrolling the border fence as well as increasing missile and mortar attacks on Israeli communities near the Gaza Strip.

Overnight Monday, the Israel Air Force struck seven targets belonging to Hamas and the other factions in Gaza Strip, including three tunnels in the northern Strip that had been dug to carry out attacks in Israel, and two buildings the IDF said had been used to manufacture and store weapons.

Yesterday's first incident occurred around 10 A.M., when the crew of a tank patrolling the northern Strip saw a group of Palestinian militants in the Sajaiyeh neighborhood east of Gaza City. They suspected the men were about to fire an anti-tank missile, and so the tank, assisted by a combat helicopter, fired at the Palestinians. Three people were hit, according to Palestinian sources.

At around 4 P.M., four mortars were fired at kibbutzim in the Shaar Hanegev region, landing in open areas and causing no injuries. The IDF fired mortars at the launching point, apparently hitting the Palestinians behind the launches but also hitting 12 Palestinian civilians, killing four.

Prime Minister Benjamin Netanyahu said yesterday that he regretted that innocent Palestinian civilians had mistakenly been hit but said "it is regrettable that Hamas continues to rain down dozens of rockets intentionally on Israeli civilians, using [its own] civilians as a human shield. Israel has no intention of bringing about a deterioration of the situation, but the IDF will continue to act with determination to protect Israeli citizens."

Later yesterday evening, a few more mortars and a Grad rocket were fired at Ashkelon. There were no injuries.

Defense Minister Ehud Barak told Fox News in an interview in New York Monday night that he hopes the situation will not deteriorate, but that he does not recommend to Hamas that it test Israel.

An investigation by the IDF's Gaza Division showed that IDF radar identified that mortars had been launched, and based on the events of the weekend, it was believed that another barrage was on the way that could hit Israeli homes. The order was given to fire at the source of the Palestinian mortar fire. One of the four mortars the IDF fired at the launch point in an olive grove strayed and hit a house about 80 meters away.

The IDF said yesterday that it only fires at populated areas to prevent immediate fire at Israeli communities.

At around 8 P.M., the IAF struck a vehicle in the Zeitun neighborhood of Gaza, killing four Islamic Jihad militants who were preparing to fire Grad missiles. The IDF believes this was the same group that fired a Grad missle at Be'er Sheva about a month ago.

IDF Chief of Staff Benny Gantz said yesterday, during a tour of the northern border with President Shimon Peres: "The IDF and the State of Israel have no interest in escalation. But if we have to, we will use harsh methods and wisely, as needed."