Nayla Moawad, Lebanese social affairs minister, said soldiers warned the protesting refugees that they would be used by Fatah al-Islam as "human shields" if they entered the camp.
Witnesses said the protesters had started to march from the nearby Beddawi camp, where they had sought refuge after the battles began on May 20.
The displaced refugees were impatient at the time they had to spend at the overcrowded Beddawi in difficult circumstances, and said they were determined to return home despite continued fighting.
Rula Amin, Al Jazeera's correspondent in Lebanon, said: "Anger and frustration are growing with each hot summer day … not only from those who are homeless but also from those who are hosting them."
However, no time frame has been announced for when the refugees can return home.
Elias al-Murr, Lebanon's defence minister, claimed victory against the armed group inside the camp more than a week ago.
But the army says that Nahr al-Bared remains a closed military zone as it tries to force the Fatah al-Islam fighters holed up inside to surrender.
The social affairs minister said: "We are very adamant when we promise that they are there [at Beddawi] temporarily. They will come back to their camp and we will rebuild what was destroyed."
Security forces are barred from entering Lebanon's 12 Palestinian refugee camps by a 1969 Arab agreement.
Much of the camp, originally home to 40,000 refugees, has been destroyed, while mines and booby traps litter its buildings and alleys.
|Protesters rushed dozens of |
injured to hospital [AFP]
A military source said Fatah al-Islam snipers killed two soldiers in sporadic fighting on Friday, raising the death toll to 203 since the start of the battles.
The clashes are part of Lebanon's worst internal violence since the 1975-1990 civil war.
At least 86 soldiers, 75 Fatah al-Islam fighters and 42 civilians have died in the fighting - mainly at the camp but also in surrounding areas.
Murr has said 300 Fatah al-Islam fighters have been killed or wounded and 40 arrested. Among those held are four Australians, two Danes and one Belgian.
A group of Muslim Palestinian leaders said it was suspending its weeks-old mediation effort to broker a peaceful end to the standoff, warning that the situation in the camp and for the displaced refugees was deteriorating.