Israel continues to bomb militant targets in Gaza early Saturday after Palestinian gunmen killed eight Israelies on Thursday.

A Palestinian man looks over the damage in Bin Zayed mosque after an Israeli air strike in Gaza August 19, 2011. [Xinhua]

The Israeli airstrikes have left 15 Palestinians dead, including some civilians, while Palestinian militant groups also launched rockets into south Israel.

In the recent Israeli attack before midnight Friday, three Palestinians were killed when Israeli airplanes struck a motorbike traveling in Gaza City.

A three-year-old boy was among the dead, said Adham Abu Selmia, spokesman for the medical services. A woman and two more bystanders were injured, he added.

Security sources said one of the dead was a militant from the Islamic Jihad movement.

Earlier on Friday night, two Palestinian activists were killed in an Israeli air strike in a central Gaza Strip refugee camp.

Witnesses in the area said that Israeli warplanes hit the militants who were riding a motorbike with a missile in the al-Buraij refugee camp which borders Israel.

Hospital sources said the activists were instantly killed.

Also on Friday, one militant was killed by a missile fired from an Israeli plane north of the Gaza Strip. One more gunman was also killed Friday afternoon in Gaza City while attempting to launch a rocket into Israel.

Israeli airplanes launched a series of airstrikes in the Gaza Strip early Friday, killing a boy and wounding others.

The 1-year-old boy, Mahmoud Abu Samra, was killed and 17 of his relatives were wounded when Israeli airplanes hit a Hamas site adjacent to their house in northwest Gaza City.

The attacks renewed after midnight, hours after an airstrike killed six Palestinians in the southern city of Rafah, including senior commanders and militants from the Popular Resistance Committees (PRC).

Thus death toll in Gaza has raised to 15 since Israel stepped attacks following well-planned operations by Palestinian militants in the Red Sea city of Eilat, where eight Israelis were killed. Israel has accused the PRC of planning the attacks.

Meanwhile, Palestinian armed groups continued launching rockets into south Israel.

An Israeli radio station reported that 21 projectiles have been fired from Gaza against Israel since Friday morning, adding that 10 Israelis were injured in the rocket attacks.

Islamist Hamas rulers of Gaza have denied any responsibility for the Eilat attack, but they did not criticize it.

In the meantime, observers in Gaza believe that the recent violence may lead to the ending of a fragile two-year ceasefire.

What strengthened this belief is the calls of some Hamas leaders on armed wing, including Hamas military wing, to respond to Israel's attacks firmly.

Gaza-based Hamad official Ismail Radwan told the Hamas-owned al-Aqsa satellite channel that the Palestinian factions have to counterattack Israel, affirming that the Israeli "enemy needs to be deterred."

The Ezz al-Deen al-Qassam, Hamas armed wing, reacted swiftly to the calls of revenge. It published a press statement in which the guerilla pledged to respond harshly if Israel's attacks continued.

Despite this tough language of responses and retaliation, some Palestinian leaders are exerting efforts to end the ongoing battle.

Well-informed sources told Xinhua that these efforts are focused on restoring calm along the Gaza-Israel borders. The sources also said that leaders in Hamas movement have contacted other factions in Gaza to cool down the situation and stop firing missiles into Israel.

Military leaders from Hamas have also met with leaders from other factions to discuss the field developments and ways to contain the heating situation in Gaza, the sources added.

But the efforts of Hamas leaders have not made any success so far because of the ongoing Israeli attacks.

Deposed Hamas Prime Minster Ismail Haniya has phoned the Arab League Secretary General, Prince of Qatar and officials in the Egyptian government and United Nations to press Israel to stop its assault on Gaza.

In Ramallah, the Palestinian National Authority (PNA) has strongly condemned the Israeli airstrikes on Gaza.

Sources close to PNA's president Mahmoud Abbas said the latter has called for an urgent session of the UN Security Council to stop the military escalation in Gaza.