Indiscriminate attacks by loyalist forces in the besieged Libyan city of Misrata, including the use of snipers, cluster bombs and artillery in civilian areas, may amount to war crimes, Amnesty International said on Friday.
The coastal city, Libya's third largest, has become one of the bloodiest battlefields in the two-month conflict, with forces loyal to Muammar Gaddafi firing from the outskirts on rebels holding the centre and port, the city's only lifeline.
Aid groups believe hundreds have been killed. Repeated air strikes by NATO have failed to silence Gaddafi's guns.
"The scale of the relentless attacks that we have seen by al-Gaddafi forces to intimidate the residents of Misrata for more than two months is truly horrifying," said Donatella Rovera, Amnesty International's senior adviser in Libya.
"It shows a total disregard for the lives of ordinary people and is in clear breach of international humanitarian law."
In a report, Amnesty accused Libyan government forces of launching "relentless indiscriminate attacks" on residential areas of the city, including the use of 122 mm Grad rockets fired from tens of kilometres away, and by mortars and 155 mm artillery shells.
"Under international humanitarian law, none of these weapons should ever be used in populated residential areas," it said.
It said it had found evidence of the use of cluster bombs, which spread 'bomblets' over a wide area, killing and wounding indiscriminately.
The report cited the deaths of a dozen residents of Misrata when several rocket salvos fell on the Qasr Ahmad neighbourhood. Many of the victims were queuing outside a bakery, it said.
Amnesty said pro-Gaddafi snipers were targeting residents in areas under the control of rebels, preventing them from moving around freely.
It urged support for investigations by the International Criminal Court (ICC) to prosecute those responsible.
Amnesty said the report was based on a visit to Misrata on April 14-20 and interviews with evacuated residents.