A Nato air strike on a city near the front line in eastern Libya has killed 15 civilians, Libya's state news agency claimed today.

Jana quoted a military official in Muammar Gaddafi's forces as saying Nato warplanes hit a number of civilian sites in the oil-refinery town of Brega today, including a restaurant and a bakery.

The official said 15 civilians were killed and 20 injured in the attack.

Jana also claimed five civilians were killed in Brega yesterday.

There was no immediate comment from Nato.

Colonel Gaddafi's government has repeatedly accused the alliance of targeting Libyan civilians in its air campaign. Nato insists it does all it can to avoid civilian casualties.

Captain Rob Leese from Nato's operational headquarters in Naples said alliance warplanes hit several targets in the vicinity of Brega, but dismissed claims that the attacks had resulted in civilian casualties.

"We have no indications of any civilian casualties in connection with these strikes," he said. "What we know is that the buildings we hit were occupied and used by pro-Gaddafi forces to direct attacks against civilians around Ajdabiya."

Meanwhile, two large explosions could be heard in the capital of Tripoli, though it was not immediately clear what the Nato airstrikes may have hit.