Mortar volleys and small arms fire persisted on the outskirts of Grozny today despite Russia's announcement of a temporary halt to air and artillery bombardment of the besieged Chechen capital, according to Chechen refugees and Russian news reports.

The fighting, part of an intricate battle for positions around Grozny that has gone on for three weeks, suggested Friday's announcement of the hiatus will not turn out to be the first step in ending the war. Fighting also raged on in the southern part of Chechnya as Russian troops pursued their campaign to smother the region's de facto independence.

"Our aims remain unchanged and they will be achieved," Acting President Vladimir Putin said, emerging from Orthodox Christmas services at Christ the Savior Cathedral in Moscow. "Have a good holiday."

Putin, in remarks relayed by Russian media, said the bombing halt was ordered for a variety of reasons: to observe concurrent Muslim Eid al-Fitr and Orthodox Christmas holidays this weekend, to avoid hitting stores of toxic chemicals the Russians say the rebels are set to unleash in Chechnya and because heavy fog makes accuracy from the air and long-range cannons impossible.

The suspension of air and artillery bombardment effectively delayed the Russian effort to conquer Grozny, the biggest urban prize of the war. Russian strategy has rested on bombarding rebel hideouts to flush defenders to the center of town while Russian units slowly advanced. Judging by the campaign so far, therefore, it seemed unlikely any progress could be made in the short term without artillery and air cover.

In Mozdok, the military headquarters for the Chechen campaign, officials issued a statement saying Russian forces used the moratorium to regroup. "Troops maintained their blockade of various localities, including Grozny, conducted intelligence operations, regrouped forces and equipment and proceed with preparations of forces for military action in mountain areas," the statement said.

Officials in Moscow went to great lengths to explain why, in the middle of a heated war, two top field commanders were replaced Friday. The commanders, Gen. Vladimir Shamanov and Gen. Gennady Troshev, were sent to posts outside the war zone.

Putin, whose popularity largely hinges on an impression of tough and competent handling of the war, seemed confused about the shakeup. In the same breath, he first denied any change had been made, then played down the transfers.

"Russia doesn't throw away such generals as Troshev and Shamanov. There has been no replacement and no replacement has been planned. It is a technical question," he said.

Both Troshev and Shamanov had dug their own wells of controversy. Shamanov, as commander of the western front, was in charge of troops who looted and killed civilians in the town of Alkhan-Yurt in early December. He had also vowed vast resignations from the officer corps if politicians in Moscow interfered with prosecution of the war.

Last fall, Troshev warned that failure to order the capture of Grozny would amount to treason. Just Thursday, the day before Troshev announced the bombing halt over Grozny, both he and Shamanov rejected a call from Chechen President Aslan Maskhadov for a cease-fire.

The ruffle of events will test Putin's image as a competent and plain-speaking leader. His performance today was something one might have expected from his predecessor, Boris Yeltsin--unclear and contradictory.

The war in Chechnya has been popular with Russians. In recent weeks however, the offensive stalled with efforts to seize Grozny. Despite Russia's overwhelming firepower from artillery and jet bombers, the rebels are taking a significant casualty toll on Russian troops--eight fatalities a day by the Russian count.

Thrusts west by the guerrillas, who supposedly were trapped in Grozny, raised the specter of the initiative passing to the Chechens. Fighting today took place in towns east of Grozny and in mountains to the south--although even there, Russian officials said fog hampered air and artillery strikes.

In Grozny, Russian soldiers described danger from ambushes and harassment from snipers. Andrei Kornev, an armored commander, said his tank has been hit three times by grenades.

"We have been fired on from two sides. It was scary, actually. I was in the driver's seat and basically pulled my crew out of there. My boys later thanked me, but at the time my knees were shaking mightily," he said on a television broadcast.

The halt to the bombing, along with the removal of the two Russian field generals, perplexed both Russian soldiers and refugees. The Russians worried that politicians were getting nervous about the course of the war while the Chechens expressed fears that after a three-day stop to the shelling of Grozny, worse is yet to come.

"We have been told that the army will be able to do what it wants, and then from nothing comes a stop in bombing and generals disappear. This seems like our usual politics," said Alexei, an officer with a communications unit at a Russian base near Chechnya's western border with Ingushetia.

"All right, they got rid of Shamanov. So bring on Stalin. That's what it will take here," said one Russian border guard, referring to the former Soviet leader's reputation for ruthlessness and his mass exiling of Chechens to Central Asia in the 1940s and '50s.

Roza Gaburayev, a Chechen refugee from Samashki, northwest of Grozny, mistrusted the announcement of a hiatus. "Believe me," she said heatedly in a conversation at the border crossing into Ingushetia, 40 miles east of Grozny. "The bombs will be falling like before. In my town, the Russians promised no shelling for a day, and an hour later, explosions everywhere."