People are fleeing in a mass spontaneous movement
West African peacekeepers in Liberia have gone to investigate reports of fighting around the town of Totota, some 80km north of the capital, Monrovia.
Tens of thousands of displaced people fled the region in the face of what they said was a rebel attack.
The BBC's Mark Doyle in Totota says that rumours of a rebel attack on a nearby refugee camp sparked off the flight, even though few of those fleeing actually heard the fighting.
He says that this latest mass spontaneous movement could risk destabilising the peace process, following last month's agreement in Ghana.
Among those fleeing were women carrying babies, a blind old man and an elderly lady in a wheelbarrow pushed by her grandson.
Relief supplies have also left for the town of Salala,
which is now hosting the fleeing people.
Moses Sidifa, a nurse, told the BBC Network Africa programme that the rebels were involved in rape and destruction of property.
"They are raping our children, 10-11 year-old children, and also women. Then they go to the villages, burn houses as well as churches," said Mr Sidifa.
It is difficult to confirm what is really happening.
All sides in the Liberian civil war have been known to terrorise civilians in order to loot their meagre belongings.
In Monrovia on Thursday, hundreds of women marched in protest at the continued fighting and looting in the country.
They carried posters with slogans like: "War, war, war everyday, we are tired".
United Nations aid officials say that the US had been asked to send helicopters from three warships offshore to reassure Liberians that the area is still safe.
Some 50,000 people were camped at Totota before reports of the shooting.
A peacekeeping force from West African countries has ended major fighting in Monrovia, although sporadic skirmishes have flared up outside the city despite last month's accord between the government and rebel groups.
An interim government meant to lead Liberia to elections in 2005 is due to take over from the caretaker President Moses Blah in October.