Gaddafi forces fire cluster bombs onto Misurata civilians

Human Rights Watch (HRW) said it saw at least three of the controversial devices - which scatter a number of smaller bomblets over the target - explode over the al Shawahda neighborhood last Thursday.

Researchers also inspected the remnants of a cluster submunition discovered by a New York Times reporter, which the group said was from a Spanish-produced mortar projectile.

The area where HRW witnessed the use of cluster munitions is near the front line in the fighting which has raged for six weeks.

However, Libyan government spokesman Moussa Ibrahim rejected the allegations.

"I challenge them to prove it, he said. "To use these bombs, the evidence would remain for days and weeks, and we know the international community is coming en masse to our country soon, so we can't do this."

Libya has invited the UN children's fund to visit Misurata and today a Red Crescent and Red Cross team will go there, he said.

HRW said it had not been able to confirm if civilians had been killed or wounded by cluster munitions in Misurata, but said their use was "appalling".

"They pose a huge risk to civilians, both during attacks because of their indiscriminate nature and afterward because of the still-dangerous unexploded duds scattered about," said Steve Goose, arms division director at HRW.

The majority of countries in the world have banned the use of cluster munitions through the Convention on Cluster Munitions, but Libya is not among the signatories.

The accusations came as Colonel Gaddafi's forces bombarded Misurata with hundreds of rockets and reportedly battled their way into the city centre.

"Today was very tough ... Gaddafi's forces entered Tripoli Street and Nakl al Theqeel road," a rebel spokesman said.

"Witnesses said they saw pro-Gaddafi soldiers on foot in the city centre today. Except for snipers, they usually stay in their tanks and armoured vehicles."

Anti-Gaddafi forces in Misurata have complained that Nato is not doing enough to help them and it was reported that a Libyan military reconnaissance helicopter was able to fly over the city on Friday.

Britain and France are seeking to convince Nato allies to provide greater fire power, but Us President Barack Obama confirmed that the US will not increases its military role.