Militants from Saraya al-Quds Brigades, armed wing of the Islamic Jihad (Holy War), claimed responsibility in a leaflet on Wednesday for firing one homemade rocket from northern Gaza Strip at the costal Israeli town of Ashkelon.

The rocket attack was carried out after Israeli Premier Ehud Olmert and Defense Minister Amir Peretz decided that Israel would adopt Peretz proposal to alter the policy of restraint to confront ongoing rockets fire on Israel.

"A directive has been given to the defense establishment to take pinpoint action against the rocket-launching squads," Israeli Daily Ha'aretz website quoted Olmert's office as saying in a statement.

The decision was made especially after two teenage boys were wounded, one of them critically, on Tuesday by a Palestinian homemade rocket that struck the western Negev town of Sderot in southern Israel.

However, the Islamic Jihad threatened to increase the rocket attacks against Israel, defying Israel's threat of targeting the militants firing rockets.

"Stop the attacks in the West Bank and Gaza Strip immediately or expect more rockets on Sderot and on Ashkelon and beyond," the Saraya al-Quds said in a leaflet sent to Xinhua by e-mail.

Israel's decision was played down not only by the Palestinian militant groups, but also the Palestinian moderates.

A senior aide to Palestinian President Mahmoud Abbas warned that the Israeli decision would have a negative effect on the results of the recent Abbas-Olmert summit held on Saturday.

Nabil Amer told Palestinian Radio "Voice of Palestine" that the Israeli decision "would lead to an atmosphere that is not encouraging".

Although chief Palestinian negotiator Saeb Erekat, who is also a senior official of Fatah, called on Palestinian militants to stop firing homemade rockets at Israel, the negotiator on the other hand urged Israel to keep restraint policy toward the Palestinians and to be committed to the truce deal reached between Abbas and Olmert.

"We were taught from the past experience that violence would drag violence, and gunfire would drag gunfire," said Erekat.

The ruling Islamic Resistance Movement (Hamas) held this time a similar stance to that was embraced by Abbas' Fatah movement.

Ghazi Hamad, spokesman for Hamas government, also called on militant groups to keep calm while denouncing the Israeli decision.

"We hold Israel responsible for the continuation of aggression against the Palestinian people," said Hamad, adding that "We still believe that this calm agreement, which was reached between President Abbas and Prime Minister Ismail Haneya, is alive."

He called on both Israel and the Palestinians to be committed to the calm agreement "because it is in the interest of our people."

Abbas and Olmert last month reached a mutual ceasefire agreement which took effect on Nov. 26, however, since then around60 rockets have been launched from the Palestinian side at Israel, according to Israeli tally.

The rockets mainly fired by some minor Palestinian militant groups, who have been demanding the expansion of the ceasefire from the Gaza Strip to the West Bank, which was rejected by Israel.