An Afghan rebel "government" that was formed to replace the communist regime in Kabul met inside the country Friday as fierce fighting raged for control of a strategic eastern city.

Only 10 of the 168 members of the rebel administration were present at the largely symbolic meeting at the Shewai rebel training camp southeast of Kabul and only 8 miles from Pakistan, where the guerrillas are based."From today, our government has begun its work inside Afghanistan," Abdul Rasool Sayyaf, the "prime minister" of the alternative government, told a news conference.

The meeting was held as rebel sources reported a fifth day of heavy fighting at the government-held eastern city of Jalalabad, where rebels Thursday claimed to have captured the airport and the old part of the city.

The sources reported heavy air bombardment Friday by government forces against guerrilla positions and said the resistance fired rockets at the city, causing massive fires.

Jalalabad's fall would be the most important victory in the rebels' 10-year-old war against the communist regime in Kabul and would deal a powerful blow to the morale of forces of President Najibullah following the withdrawal of Soviet troops backing his government.

The guerrillas control 80 to 95 percent of Afghanistan but have refrained from attacking major cities in recent months, in part to allow Soviet troops to withdraw unhindered.

President Najib asked the United States and the Soviet Union Friday to intervene to stop the guerrilla attacks.

"As one of the guarantors of the Geneva accords, I ask you, in light of your responsibility, to take immediate necessary measures and prevent, by every possible means, a further intensification and aggravation of the situation," said Najib's message, read on Kabul radio and monitored by the BBC.