Suspected members of a militant Islamic group fired a rocket-propelled-grenade at a Lebanese army checkpoint Sunday near a Palestinian refugee camp close to this southern city, wounding at least five people, security officials said.

Three Lebanese soldiers and two Palestinian passers-by were wounded in the attack in Taamir, a residential area adjacent to Ein el-Hilweh camp, hospital officials said, speaking on customary condition of anonymity.

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Security officials, speaking on condition of anonymity because they were not authorized to speak to the media, said the troops returned fire at the suspected Jund al-Sham militants.

The attack comes as Lebanese troops are launching a major attack on another militant Islamic group, Fatah Islam, in the Palestinian refugee camp of Nahr el-Bared near the northern city of Tripoli.

An hour after the grenade attack, gunfire could still be heard near the camp on the southern outskirts of the city. The officials said militants were shooting at army positions from the roofs of several buildings.

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Hundreds of Lebanese and Palestinian civilians who live in Taamir and inside the camp were seen fleeing tense areas. Some took shelter in mosques, while others stayed in the street in safer areas in Sidon.

The officials said the army was sending reinforcements to the area, and vehicles, including armored personnel carriers, were seen rushing to Taamir.

Sultan Abuleinein, head of Palestinian President Mahmoud Abbas' mainstream Fatah faction in Lebanon, told Lebanese Broadcasting Corp. television, that his group will do its best to prevent the spread of violence to camps near Sidon.

"We are taking some measures on the ground to pull away these members and we will not allow this gang to drag the camp into a clash with the Lebanese army," Abuleinein said. He did not elaborate on what measures are being taken but said "we have taken measures to prevent any party from attacking the Lebanese army."

It was not clear if the attack was related to the conflict in the north, but several hardline Islamic groups have called on Muslims to support Fatah Islam.

Late Thursday, a gunbattle erupted in the Ein el-Hilweh camp between the Jund al-Sham group and Fatah.

Jund al-Sham, which is Arabic for Soldiers of Historic Syria, has claimed responsibility or been blamed for a number of bombings and gunbattles, mainly in Lebanon and Syria. Syrian officials have portrayed it as the most active militant group in their country.

Also Sunday, the Lebanese army bombarded Fatah Islam militants in the Nahr el-Bared camp with heavy artillery in the third day of a major offensive aimed at crushing the al-Qaida-inspired group.

Since the standoff with Fatah Islam began two weeks ago, the army has suffered 44 casualties, and at least 20 civilians and some 60 militants have also been killed.

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