Muslim guerrillas said they shelled the heavily fortified Afghan city of Jalalabad with surface-to-surface rockets on Saturday to prepare for another major offensive.

Afghanistan's Communist-style government retaliated by heavily bombing guerrilla positions around the eastern city."This is just a test run to gauge the government's strength and retaliatory strikes," said Sheen Gul, a guerrilla commander.

Earlier this week, government warplanes stopped a 10,000-strong guerrilla assault on Gardez, 90 miles south of Jalalabad, the capital of Nangarhar Province.

Gardez, the capital of Paktia Province, is the hometown of several senior government officials, including Afghan President Najibullah.

Muslim insurgents said their original battlefield strategy was to launch simultaneous attacks on several Afghan cities to unnerve the government and stretch its air power.

"Jalalabad and Gardez should fall together. That was our dream," said Abdul Rahim, a spokesman for the devout Muslim rebel group Jamiat-i-Islami, or Party of Islam.

But feuding factions within the Afghan resistance delayed the assault on Jalalabad, the scene of a failed assault that became one of the bloodiest battles in Afghanistan's 13-year-old war.