BEDDAWI, Lebanon - Relief workers on Saturday accused the Lebanese army of using "excessive force" to disperse a protest in which dozens of displaced refugees in northern Lebanon were killed or wounded.

"The protesters were more than 10 metres away from the (army) checkpoint and there was gunfire," said Caoimhe Butterly, an Irish member of the Nahr al-Bared Relief Campaign, a non-governmental organisation.

Mahmud Halimi, the NGO's coordinator, called for an independent probe into Friday's violence as Palestinian refugees demanded the right to return to the Nahr al-Bared camp where troops have been battling Islamic militants since May 20.

"The demonstration was going peacefully and unarmed. The soldiers fired first in the air. We sat down to de-escalate, but after that there was gunfire at the demonstrators. There was no communication before opening fire," he said.

"Men, women and children were victims of an excessive use of force. We ask for an independent investigation," Butterly told reporters in Beddawi, a Palestinian camp near Nahr al-Bared and close to the scene of the violence.

Medics said three people were killed and about 40 wounded as the demonstration by hundreds of refugees who fled Nahr al-Bared came under fire from Lebanese soldiers at a checkpoint outside Beddawi.

The Palestinians killed were to be buried later on Saturday.

A wounded Palestinian, Salim Shamaa, said, "I got shot because I was raising my hand to talk to the people," while 22-year-old Mohammed, who declined to give a family name, said he was knifed by Lebanon counter-demonstrators.

"People are very angry. They thought they had left Nahr al-Bared to be safe ... The last thing they thought was they could be killed or wounded by coming here," said Mona Waked of the UN relief agency for Palestinian refugees, UNRWA.

But the Lebanese army insisted its troops had taken all necessary measures to avoid casualties among the protesters.

"They were trying to force their way through the checkpoint, carrying metal objects and sticks, ignoring warning shots in the air," an army spokesman told AFP. "The whole incident is not clear yet."

The military said the protesters marched out of the overcrowded Baddawi camp and tried to block the main highway with tyres to press their demand to return.

Abbas Zaki, the Palestine Liberation Organisation's (PLO) representative to Lebanon, accused "anarchic elements of provoking these incidents by infiltrating a peaceful demonstration".

He refused to blame the army. "We will give the army the time and chance to complete their mission," said Zaki.

But the Damascus-based Popular Front for the Liberation of Palestine-General Command (PFLP-GC) held the Lebanese government responsible for the killings and called for an Arab investigation.

"We pin responsibility for the Beddawi massacre on the Lebanese government," it said in a statement.

The PFLP-GC called for an "Arab inquiry into the crime, ranging from attacks on the Lebanese army to the violations of the civil and humanitarian rights" of the refugees of Nahr al-Bared and Beddawi.

Less than 1,000 civilians of Nahr al-Bared's normal population of about 31,000 have stayed put, with the rest fleeing from a showdown between the army and Islamists, mostly to take shelter in Lebanon's other Palestinian camps.

The militants of "Fatah al-Islam are criminals and need to be wiped out. They are causing division between us and the Lebanese," Mustapha Ibrahim, 55, another resident of Nahr al-Bared, said ahead of the demonstration.

Soldiers and fighters inside the camp traded sporadic gunfire on Saturday, a correspondent at the scene said, in the latest episode of the six-week battle that has reduced much of the Palestinian camp and refugees' homes to rubble.

According to a count compiled from official figures, the fighting has cost at least 169 lives, including 84 soldiers, in and around Nahr al-Bared. The toll does not include the corpses of several fighters abandoned in the camp. -AFP