Russia's military pushed forward yesterday with its drive to capture Chechnya's capital, Grozny, and its southern mountains, but reports from the rebel region said separatist guerrillas were offering stiff resistance.
One day after the acting President, Mr Vladimir Putin, paid a morale-boosting visit to Chechnya, private NTV television said troops were being beaten back in attempts to take control of some key districts of Grozny.
It said poor co-ordination and communications had led to some soldiers coming under artillery fire from their own side.
The report, from an NTV correspondent in the region, could not immediately be confirmed independently.
The army had earlier accused the Muslim rebels of detonating bombs containing toxic chlorine and ammonia in Grozny. NTV said that report could not be confirmed.
Mr Putin's New Year's Eve visit to Chechnya took place hours after the surprise resignation of Mr Yeltsin.
Mr Putin's tough stand during the three-month-old drive into Chechnya has made him Russia's most popular politician and a favourite to win a presidential election now due in March.
The NTV report said Interior Ministry troops had suffered 1,500 injured in the three weeks since the military first surrounded Grozny, also the site of fierce battles in Russia's disastrous 1994-1996 war against Chechen separatists.
NTV quoted Russian servicemen as denying official reports that Moscow's forces had full control of Grozny's north-western Staropromyslovsky district. They said the Chechen guerrillas had set up reinforced positions which Russian artillery had failed to penetrate.
"They had reinforced concrete trenches," Lieut Konstantin Kukhonavets, a platoon commander, told NTV. "It was a good thing we did not go any further into that trap or we would never have got out."
The television quoted doctors at military hospitals in Moscow and the Urals city of Yekaterinburg as saying no spare beds were available to treat the wounded.
It also said pro-Moscow militias, supposed to assist Russian forces, had turned and fled after coming under fire. But NTV said Russian forces had taken control of Tashkala district overlooking key points in Grozny and killed 300 fighters in battles to flush rebels out of mountain strong holds.
During a visit to the Russian-controlled town of Gudermes, east of Grozny, Mr Putin said there was no time limit to take Grozny and promised to limit losses among Russian forces and among civilians. From 10,000 to 40,000 civilians are estimated to be in Grozny.
Itar-Tass news agency, in a report earlier yesterday quoting Russian regional headquarters, said rebels had set off several toxic bombs near Russian positions in the east. It said the wind had blown a green cloud over the rebel-held city centre.
It was the third time the Russian military had reported such an attack during its week-long assault on Grozny.
Tass said the troops were equipped for chemical attacks and had not been affected, but that the cloud could be a danger for thousands of civilians trapped in central Grozny.
Tass quoted the regional military command as saying eight Russian servicemen had been killed and 16 wounded in the last three days of fighting.
Meanwhile, the Turkish Foreign Minister, Mr Ismail Cem, expressed concern that the conflict in Chechnya would have a negative effect on neighbouring countries of the Caucasus, primarily Georgia.
Georgia, which Turkey considers an ally and which has its own differences with Moscow, has hosted some 5,000 Chechens who have fled fighting between Russian troops and Muslim rebels in the war-torn region.
"I believe the priority issue for us in 2000 will be Georgia and the southern Caucasus," Mr Cem added.
"The children that are being killed, the women that are being massacred and the civilian settlement areas that are being bombed in Chechnya are, of course, not Russia's domestic affair," Mr Cem said.
"These issues concern all of us because this is a human rights and democracy problem," he added.
Dozens of people gathered in Istanbul to protest against Russia's campaign in Chechnya, Anatolia news agency reported.