A senior Hamas official warned on Wednesday that the ongoing Israel Defense Forces raids on the Gaza Strip could turn negotiations over the release of abducted soldier Gilad Shalit into "a Ron Arad affair."

The warning was in reference to the Israel Air Force navigator who has been missing in action since his plane went down over Lebanon in 1986.

In an interview aired on Channel 1, Hamas official Ismail El-Muzeini, who is overseeing the Shalit matter for the group, said that if the raids continued, Hamas would cut off all contacts with Israel over the release of Shalit, who the group has been holding captive since 2006.

Earlier Wednesday, Hamas' exiled leader Khaled Meshal that IDF raids on Gaza would hurt chances of the Palestinian militant group releasing Shalit.

Meshal told reporters that recent IDF operations in the coastal strip also made Hamas less likely to negotiate any truce with Israel.

Speaking to Israeli leaders, Meshal said: "What you are doing will deny you of any plan you could be betting on: No exchange for Gilad Shalit and no truce."

The militant leader's comments at a news conference in Damascus, where he lives, came as IDF troops continued a second day of raids in Gaza, which has been under Hamas' control since the group's forces ousted Palestinian President Mahmoud Abbas' Fatah movement from the strip in June.

Israel Air Force aircrafts fired repeatedly at Palestinian rocket squads Wednesday in northern Gaza, killing five people, including three civilians, as rockets and mortars sailed across the border into Israel.

On Tuesday, 19 Palestinians were killed in the bloodiest day of fighting since Hamas took control there.

At the news conference, the exiled militant leader said, "Palestinians blood won't save Israel's leaders, but will drown them."

Meshal also criticized Abbas' response to the Gaza fighting. The Palestinian president has condemned Israeli incursions into Gaza, but senior Abbas aides have said he will not halt peace talks with Israel.

"A genuine response to the massacres would be to halt the futile negotiations [with Israel]," Meshal told reporters.

Officials Israel's defense establishment earlier voiced concerns that Tuesday's fighting in the Gaza Strip, which left at least 19 Palestinians dead, will impact negatively on the efforts to gain the release of Shalit.

In fighting Tuesday, 19 Palestinians were reported killed, 15 of whom were confirmed to be armed militants. A volunteer from Ecuador working near Kibbutz Ein Hashlosha, was shot and killed by a Palestinian sniper.

Tuesday's fighting had left officials in Israel's defense establishment pessimistic about the important progress in the negotiations for the release of Shalit.

Contributing to this assessment is the fact that one of the Palestinian militants killed Tuesday is Hussam Zahar, son of the former Palestinian Authority foreign minister in the Hamas-controlled government, Mahmoud Zahar.

Mahmoud Zahar is considered to be a firebrand and one of the leaders of the more extremist wing of Hamas, with close ties to the military wing of the organization.

Security sources emphasized Tuesday that Hussam's killing had not been planned. He was among a group of Hamas gunmen who sought to prevent an elite unit of the Golani Brigade from entering the neighborhoods of Saajiye and Zeitoun in Gaza City, and he was killed in the exchange of fire.

The same sources said that, at this stage, the Israel Defense Forces and the Shin Bet do not consider the senior figures in Hamas as targets, and stressed that the Hamas militants killed Tuesday lost their lives in fighting with IDF forces or because they had been targeted while they tried to launch rocket and mortar attacks against Israeli towns.

Following news of his son's death, Zahar told Al-Shams, a Nazareth-based radio station Tuesday that "there is no immunity to a nation that provides support and legitimacy to a government that murders children and the elderly and agrees to besiege an entire people."

The Hamas leader blamed the Palestinian Authority government in Ramallah for what is taking place in the Gaza Strip: "There are people in that government who parachuted upon us in American parachutes and there are people linked to the United States by their umbilical cord, and I expect Abu Mazen [PA President Mahmoud Abbas] to condemn the murder of his people and demand the lifting of the siege, but he is not doing this."

Like other Hamas leaders, Zahar claimed that the IDF attacks in the Gaza Strip were the result of a "green light" given to Israel by President George Bush during his visit in Israel last week.

Zahar also blamed Egypt of collaborating with the U.S. and Israel in refusing to allow Palestinian pilgrims to Mecca from reentering the Gaza Strip through the Hamas-controlled Rafah crossing.

Fighting begins Tuesday The fighting began Tuesday when an elite unit of the Golani Brigade infiltrated the environs of the neighborhood of Zeitoun, and took up positions there. At first light, Palestinian gunmen were seen in the area and they were attacked by the IDF unit, resulting in a gun battle that lasted most of the day.

At approximately 8:30 A.M., the air force targeted a vehicle moving in the area of the fighting with five gunmen. At about 9 A.M., the air force attacked another group of Palestinians preparing to fire mortars at the IDF troops in the area.

At 9:45, a Palestinian sniper shot and killed a volunteer from Ecuador who was working in a potato field near Kibbutz Ein Hashlosha.

At 3 P.M. the Palestinians fired a Katyusha against Ashkelon. An hour later the IDF units operating near the Zeitoun neighborhood began their withdrawal into Israel, which was followed by extensive rocket and mortar attacks.

Close to 6 P.M., the air force attacked a crew firing Qassam rockets, killing at least two.

The immediate Hamas response to the fighting in the Gaza Strip, has been the launching of Qassam rocket and mortar attacks against Israel. SEE Story Page 2.

Four residents of Sderot suffered light injuries as a result of the rocket barrage and significant damage was caused to houses in the town.

Also Tuesday, Hamas fired a Katyusha rocket which landed south of Ashkelon.

More than 20 rockets and some 30 mortars were fired Tuesday.

Defense establishment officials said Tuesday that they do not believe Hamas is interested in escalating the situation at this time, drawing the IDF into a large-scale ground offensive in the Gaza Strip that would result in the reoccupation of the Strip.

Inside the organization, a disagreement is evident over whether to pursue intensive efforts to resume suicide bombings. However, Israeli security sources say that, for now, it appears that most of the attacks will continue along the border of the Gaza Strip.

The IDF is also not planning to alter its current modus operandi, characterized by ground forces raids, limited in both time and scope, and in assassinations of militants in the Islamic Jihad and the Popular Resistance Committees, as well as Hamas Qassam-rocket crews.

Senior sources in the defense establishment said Tuesday that the current timing is not conducive for an extensive ground operation, but it may be in a few months if the escalation in rocket attacks continues.

The firing of the Katyusha rocket at Ashkelon, the second instance in as many weeks, is evidence the city is permanently within the scope of Hamas and that attacks depended on decisions made by the radical Islamist group.