Hezbollah warned Israel on Saturday not to use an incident in which rockets were fired from southern Lebanon into the Jewish state as a pretext for sparking a conflict with the Shi'ite guerrilla group.

Hezbollah, a potent military and political force, said it was ready to react forcefully in the event of an Israeli attack.

At least three Katyusha rockets were fired into northern Israel from southern Lebanon on Thursday, in an attack seen as linked to Israel's offensive in the Hamas-ruled Gaza Strip.

Hezbollah, which still maintains a stronghold in the south, has denied responsibility for the attack which wounded two people. The Lebanese government condemned the attack as a violation of a U.N. Security Council resolution that halted the 2006 war between Israel and Hezbollah.

Even before Thursday's incident, the Gaza fighting had increased tension along the Lebanese-Israeli border with both Hezbollah and Israel on guard.

"We are prepared to face any foolishness. We have wisdom, composure and strength which allows us to deal with calmness of nerves. We will not be dragged into what we don't want or what we don't decide ourselves," said Mohammed Raad, the head of Hezbollah's parliamentary bloc.

"We will not allow ourselves to be targeted under any circumstances, either under the pretence of unknown rockets or under the pretence of the elation of victory here or there."

Raad appeared to be referring to a scenario in which, should Israel declare victory in Gaza, it would then attack Hezbollah, which stood its ground in the 34-day war in 2006.

"We are on the lookout for the Israelis. And we will prove that this preparedness is bigger and greater than the enemy can imagine," Raad told a mass Shi'ite gathering in the southern town of Nabatiyeh.

Israel has mobilised tens of thousands of reservists since beginning the Gaza ground offensive. The army has not said where they will be deployed, but there has been speculation in Israeli media that some will be stationed in the north.

Hezbollah put its fighters on alert early in the conflict, wary that Israel's Gaza campaign could mark the start of a wider offensive against its foes.

Hezbollah, which like Hamas is backed by Iran, has said it is confident the Islamist group will emerge victorious in the Israeli onslaught on Gaza that began on Dec. 27.

Hamas officials say the Israelis have so far killed 821 Palestinians, many of them women and children. Ten Israeli soldiers and three Israeli civilians have also been killed.