Colonel Muammar Gaddafi's forces have carried out an airstrike close to a military base held by rebels in the east of Libya, witnesses said.
It was the second day in a row the dictator's air force has reportedly bombed the town of Ajdabiyah as he tries to clampdown on the uprising.
A warplane struck just outside the perimeter of the Haniyeh base which stores large amounts of ammunition, but did not hit it, rebels said.
"We were sat here, heard the jet, then the explosion and the earth shook. They fell outside the walls," said Hassan Faraj, who was guarding the facility.
Another volunteer guard, Aziz Saleh, said two rockets had been fired. They had landed just outside the walls of the base, he said.
Opposition groups have called for a no-fly zone in Libya to prevent air attacks by pro-regime forces.
And they say they will only talk to the government if Col Gaddafi resigns or goes into exile.
Western nations have urged the dictator to quit and are considering various options including a no-fly zone.
But they are wary of any military move which may further destabilise the country.
Earlier in the day, rebels said they were preparing for further attacks by troops loyal to Col Gaddafi.
Anti-regime forces who control the key port city of Zawiyah, outside the capital Tripoli, said they had already started to launch counter-attacks against soldiers who had begun to gather in the area.
One resident of Zawiyah said an estimated 2,000 troops had positioned themselves to the south of the city with 80 armoured vehicles headed there from the east.
In the east of the country, witnesses reported an air raid on the key oil town of Brega for the second day in a row on Thursday.
Col Gaddafi's son Saif told Sky News these raids were designed only to intimidate the rebels rather than cause deaths.
Brega has seen violent clashes between pro and anti-Gaddafi forces. It is believed a man from Manchester may have been killed there.
Aid agencies have warned that as well as the help required by the thousands of refugees trying to escape the fighting, they believe assistance is desperately needed inside Libya.
Ivan Gayton, from Medicins San Frontieres, told Sky's security editor Sam Kiley that Col Gaddafi was preventing help reaching those who needed it.
He said: "The crisis is in Libya. Our colleagues tell us that they need help to treat the wounded."
Mr Gayton added: "There are wounded people, perhaps in fairly large numbers... we have a surgical team, we have six tonnes of medical supplies... we're being blocked, we can't access them."
US President Barack Obama said the international community must be ready to stop violence against Libyan citizens.
Britain and France have continued to pledge their support for the establishment of a no-fly zone if required.