GROZNY -- Russian planes screamed over the Chechen capital Thursday, dropping bombs and firing missiles, which flattened houses and gouged into apartment blocks, killing at least 18 people caught out in the streets in the first daytime raids on the city.


Terrified people scrambled for cover as the planes came over again and again. Several people sifting through the debris caused by the first raid were caught when the jets made second and third sorties, dropping their bombs in the same places as before.


Some of the dead were burned in their cars, others were crushed by collapsing buildings or torn apart by flying shrapnel.


Among the dead was a 28-year-old American freelance photographer, killed instantly by a bomb that landed near her. Her name was being withheld until her relatives were informed. This was the heaviest bombardment yet of Grozny, marking a sharp escalation in Russia's assault on the capital of the breakaway republic.


Artillery based in the surrounding hills lobbed shells indiscriminately into central residential areas.


President Boris Yeltsin, who ordered thousands of troops into Chechnya on Dec. 11, sent a letter to the State Duma on Thursday saying he would address the Russian people in the coming days with plans to resolve the conflict "based mainly on using political methods," Reuters reported.


However, Russia planned to bombard Grozny again throughout the night Thursday, Interfax quoted an unnamed high government official as saying.


And in the Chechen capital, The Associated Press reported that residents were fleeing the city for nearby hills any way they could. People desperately flagged down cars. Women and children rode on sacks of flour on trailers being dragged by tractors.


Smoke billowed over the city from the numerous explosions, which at one point came every 30 seconds, the AP said. Some people slipped on the shards of glass sprayed across the icy pavement.


The city center on Thursday looked, felt and smelled like a war zone. Ash from the numerous fires caused by the bombing had turned the snow black, broken glass crunched underfoot and torn-down trolley-bus lines trailed in the streets. Trees snapped off by the explosions left ragged, gleaming yellow stumps.


One apartment building near the presidential palace was reduced to a mound of rubble, broken rafters poking out skywards from the wreckage.


"This is Russia's New Year present," said one man in a crowd of people surveying the damage from the raids, which began just before midnight Wednesday. The night raids appeared to be aimed at specific targets, such as the presidential palace and an oil refinery in the southwest of the city, which was hit and set on fire, lighting the sky with an orange glow.


Later, Reuters quoted a local journalist as saying that the refinery had only suffered minor damage and was functioning normally Thursday.


He told Reuters by telephone that the attacks were not aimed directly at Grozny's main refinery and damaged only two nearby oil pumps about five kilometers southwest of the city center.


Alexander Shevchenko, 75, a Russian, said he had felt the blast that destroyed the apartment building from the next door building where he lived. "It was terrifying, terrifying," he said, his whole body shaking. "They are not people who are doing this. They are wild and savage."


As he spoke, Russian jets roared in once again, sending the crowds running for cover. It was midday. Some kiosks and shops had opened and many people were out on the streets to buy bread and any other food they could find.


But the mood of the people remained defiant. "Not one Chechen will give up," said Umar Dendi, 50, a member of the Chechen parliament, who had come out of the presidential palace to survey the damage. "I know the mood of these people; they talk to me. And they all say they will never disarm."


His words were echoed by Rizvan Abdulkhanov, 57: "We will fight a guerrilla war after this," he said.


But for the time being, the Chechen fighters were helpless. Bewildered men stood at their positions, not firing and wondering what to do, AP reported. Anti-aircraft guns were silent due to an ammunition shortage.


It was impossible to determine how many jets were involved in the repeated attacks because of the low clouds, but one correspondent counted 12 planes.


In one sortie, a jet fired two rockets into a northern residential district, then swung around and fired another rocket into a crowd of people who gathered to inspect the damage, AP reported.


It was the third consecutive day of air raids on Grozny. Chechen officials said 100 people, including 17 children, were killed late Wednesday and early Thursday. The attacks have destroyed and damaged numerous apartment buildings as well as military targets.


Russian President Boris Yeltsin sent an estimated 10,000 to 40,000 soldiers into Chechnya on Dec. 11 to disarm separatists. Chechnya declared independence from Moscow in 1991, but Moscow has refused to let it leave the Russian Federation.


Grozny had a population of some 300,000 people before fighting broke out, but an estimated 67,000 to 100,000 have fled in recent weeks for the countryside or neighboring Ingushetia.