The relative quiet along the Israel-Gaza border that has prevailed since the Cast Lead operation faced its most severe threat to date on Tuesday morning when a Qassam rocket fired from Gaza landed close to a preschool in the Israeli kibbutz Zikim just south of the coastal town of Askelon, slightly injuring a 13-year-old girl.

Such attacks used to be a daily feature in the lives of the Israelis living in the areas surrounding Gaza, but following the highly controversial Israeli military offensive that ended in January 2009, missiles and mortars fired from the Palestinian enclave have decreased significantly.

However, a recent string of attacks on both military and civilian targets has caught the attention of Israel's political and military echelon, with officials quoted as saying that Hamas is trying to change the rules of the game both in terms of strategy and types of weaponry used.

While Hamas is not believed to be behind Tuesday's rocket attack, Israel still holds them responsible following the organization's military takeover of Gaza from its political rival Fatah in 2007.

Analysts were concerned that a major escalation, but not a full- fledged war, could be possible in the near future if the tension is not defused.

A vicious circle

The relative calm along the border last year is illustrated by numbers published in the Israeli daily Ha'aretz, which reported that so far in 2010, 180 rockets and mortars from Gaza have landed in Israel, plus an additional 200 that landed in Gaza due to errors. By comparison, 2008 saw an estimated 4,000 projectiles fired towards Israel.

Naji Shurab at Al-Azhar University in Gaza said that there is a risk that the current attacks will escalate.

"This escalation may lead to an overall confrontation between Israel and Hamas, because it's quite difficult to control," Shurab said.

One possible scenario that could trigger such a development, according to Shurab, is if a rocket launched by one of the Palestinian resistance groups or Hamas causes a large number of casualties to which Israel would retaliate forcefully, causing the situation to spin out of control.

Asked in what way Israel might reply to a major attack from Gaza, Shurab speculated that it may range from a ground invasion similar to Cast Lead, or Israel may return to the controversial method referred to as "targeted killings" to take out key members of Hamas and other Palestinian groups.

Targeted killings are contentious because innocent bystanders are often injured or killed by missiles fired from Israeli aircraft. Human rights groups have also classified the method as extrajudicial killing because it does not involve a trial.

Gabriel Ben-Dor of the department of political science and the director of the National Security Studies Center at the University of Haifa also believes that the situation along the border does not look good.

Ben-Dor said the Palestinians are "on the borderline of provoking another military action" by Israel, but not an all-out war.

One major difference in the latest rounds of attacks is that "the level of violence has escalated and the technology used by Hamas in its rockets has escalated as well to the point where they would threaten Israel's critical security interests," Ben-Dor said.

Hamas is blamed for attacks on Israel

Following Hamas' military takeover of Gaza in 2007, Israel argues that the organization is the de facto government of the coastal region and as such is responsible for all rockets fired from it, regardless of whether it was carried out by members of Hamas or any other group.

"Hamas is the government that governs Gaza and is the most powerful group in it," Shurab said, adding that they are capable of controlling the other groups and preventing them from launching rockets.

However, this does not mean that Hamas is interested in doing so. Shurab believes that Hamas cannot be seen as denying the other groups of their rights to military action, otherwise it will be perceived as having given up armed resistance.

Shlomo Brom, a senior research fellow at the Institute for National Security Studies at Tel Aviv University and director of its program on Israel-Palestinian relations, told Xinhua that so far the two parties are not interested in a major new conflict.

But Brom warned that in such situations there is always a risk of miscalculation by one of the parties that may force the other to react strongly, leading to the possibility of an escalation that cannot be controlled.

"I think that Hamas is in strong control of Gaza. If they are interested, they may not be capable of preventing 100 percent of the operations against Israel but it will be very close to 100 percent," Brom said.

Asked if there's a possibility for the parties to defuse the tension, Brom argues that if "Hamas reins in the organizations that are sending different projectiles to Israel, then the tension will disappear."

However, according to Shurab, this is more easily said than done as Hamas needs to maintain its position within Palestinian society.

"The dilemma of this escalation is that Israel wants to send a message to Hamas that they will not allow for any show of force from Hamas or any other Palestinian resistance group," Shurab said, "meanwhile, Hamas wants to be assured that its option of resistance is still alive."