Although there were no Israeli fatalities in the firing of the so-called Qassam missiles, five soldiers were slightly wounded and the country’s sixth largest city also came under attack.
The main Palestinian militant groups have been observing a ceasefire since the start of the year while Israel had largely held off arrest operations in the West Bank except against members of the small Islamic Jihad movement.
The unofficial deal however appears to be unravelling fast, with Israel voicing fears of an explosion in Palestinian violence ahead of legislative elections in five weeks’ time.
Five soldiers wounded
It was not immediately clear which Palestinian factions were behind the latest rocket attacks into southern Israel, launched from northern Gaza.
One of the Qassams, which take their name from the armed wing of the Islamist movement Hamas, lightly wounded the five Israeli soldiers when it landed on their base near the border.
That attack came just hours after another of the missiles exploded near an industrial zone in the southern Israeli city of Ashkelon, which lies around 10 kilometres north of Gaza.
The rocket landed next to a fence around a major electricity station which supplies a large part of southern Israel.
It is the third time in less than a week that a Qassam has landed on the outskirts of Ashkelon.
Three more Qassam rockets fired from the Gaza Strip landed in southern Israeli desert territory late Thursday causing no injuries or damage, an Israeli military source said.
Finance Minister Ehud Olmert was quoted as saying by Israeli public radio on Thursday night that “Israel will retaliate severely to Qassam rocket fire, by a land military offensive if needed.”
Transport Minister Meir Sheetrit, a close ally of Prime Minister Ariel Sharon, said the population of Gaza must be taught a lesson.
“There is no justification for the continued fire on us. We must respond with severity,” Mr Sheetrit told the Ynet website.
“We must force the concentrated Palestinian population that resides near the border to leave their homes and move out. If we can’t sleep in peace, they won’t be able to sleep peacefully either.”
Mr Sharon has previously pledged that he would not allow Ashkelon to become a “frontline” city in the conflict with the Palestinians and respond with an iron fist to attacks now that Israel has left Gaza.
Deputy defence minister Zeev Boim confirmed that the idea of severing electricity supplies had been discussed recently. All of Gaza’s electricity is supplied by Israel.
Israel has so far responded to the rocket attacks by firing artillery into uninhabited areas and launching air strikes on remote rocket launch sites but chief spokesman Avi Pazner said the response would now be much harsher.
“We will take much tougher measures than in the past to stop this action,” he said. “Terrorist groups must understand they cannot bomb Israel with impunity.”
The government has so far rejected any idea of re-invading Gaza but calls for such action are growing.
Ehud Yatom, a former head of the internal security service Shin Beth and now an MP for the right-wing Likud Party, said it was time to send troops back in.
“The state of Israel should order the IDF (army) to hit the terror infrastructure in a combined aerial and ground operation to bring back security to Israeli citizens,” Mr Yatom said.
While Israeli troops have all withdrawn from Gaza, they continue to operate in the West Bank, including the largest city of Nablus where three militants were killed on Thursday.
The local military leader of the leftist Popular Front for the Liberation of Palestine and two members of the Al-Aqsa Martyrs Brigades, an offshoot of the ruling Fatah faction, were shot dead as they tried to break out of a building besieged by Israeli troops.
A Palestinian was also killed in an explosion in northern Gaza. The
Palestinian interior ministry said it was investigating whether the 21-year-old was a victim of Israeli fire or if he had been killed when a device that he had been handling exploded.