TRIPOLI, LIBYA (CNN) -- Forces loyal to Libyan ruler Muammar Gaddafi pummeled the city of Misrata with rockets Saturday, a witness said -- a day after a human rights group said government troops fired cluster bombs into civilian areas there.

The witness, who did not want to be identified for security reasons, estimated more than 100 Grad rockets fell in the besieged western city as rebels tried to hunt down pro-Gaddafi rooftop snipers. There was no immediate word on casualties.
For weeks, witnesses in Misrata have reported dire conditions during the Libyan war, including food shortages and the chronic fear of pro-Gaddafi snipers taking aim at anyone walking on the streets. A clinic director said at least 700 people have died since the violence erupted in Misrata two months ago, and a doctor in the city said medical teams are exhausted from treating the wounded.
The witness said the port of Misrata was still in the hands of rebels Saturday, but Gadhafi's forces shell it everyday to try to cut off humanitarian aid to enter the city.
CNN could not independently confirm the report from Misrata on Saturday. But on Friday, Human Rights Watch said Gadhafi's troops have used internationally-banned weapons on the besieged city.
The organization said in a statement that it saw three cluster munitions explode over the el-Shawahda neighborhood of Misrata on Thursday night. Researchers inspected debris from a cluster submunition and interviewed witnesses to two other apparent cluster munitions strikes, the statement said.
Human Rights Watch inspected the submunition, which it said had been discovered by a New York Times reporter, and determined that it was a Spanish-produced MAT-120 120mm mortar projectile, which opens in the air and releases 21 submunitions across a wide area.
The submunitions explode on contact, disintegrating into molten metal that can strike people and penetrate armored vehicles, the group said.
“It's appalling that Libya is using this weapon, especially in a residential area,” said Steve Goose, arms division director at Human Rights Watch. “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.”
Most nations have banned their use through the Convention on Cluster Munitions, which became international law in August. Human Rights Watch said cluster munitions were used about a kilometer from the battle line between rebel and government forces and appear to have landed about 300 meters from Misrata Hospital.