Russian officials said there would be no withdrawal of forces from Chechnya and ruled out a mediation role for the Organization for Security and Co-operation in Europe - an apparent concession by Moscow on Thursday.

"The task remains unchanged - to destroy the militants," said Russian Interior Minister Vladimir Rushailo.

The BBC's Bridget Kendall: "Relief rather than jubilation"

"We don't need any mediation," Mr Rushailo told reporters in Moscow, when asked about a possible OSCE role.

The two accords signed on Friday - after a day's delay caused by disputes with Russia over Chechnya - were:

• a Charter for European Security, which establishes the principle that conflicts in one state are the legitimate concern of all
• An updated version of the 1990 Conventional Forces in Europe (CFE) treaty, which sets lower ceilings for key armaments and troops stationed in militarily sensitive border regions.

OSCE Chairman Knut Vollebaek talks to BBC World Service Newshour

A declaration on Chechnya adopted at the end of a summit of the OSCE summit stated: "We agree that a political solution is essential and that the assistance of the OSCE would contribute to achieving that goal...We welcome the agreement of the Russian Federation to a visit by the (OSCE) Chairman in Office to the region."

The head of the United Nations refugee agency, Sadako Ogata, said in Moscow on Friday, after visiting refugee camps on the Chechen border, that the situation there was not castastrophic.

However, she told the Russian Prime Minister, Vladimir Putin, of her serious concern about the number of civilian casualties.

No timetable for negotiations

The BBC's Chris Morris: "Russia is already violating the agreement"

But no timetable has been agreed for any political talks and Moscow continued to describe the government of the breakaway republic as bandits and terrorists.

Even as the negotiations were taking place Russian troops were continuing to pound the Chechen capital, Grozny.

Interfax news agency said Russian warplanes had carried out about 60 air strikes during the past 24 hours.

Click here to see a map of the region

Correspondents point out that the promised invitation to the Norwegian chairman of the OSCE, Knut Vollebaek, to visit the region does not guarantee he will be allowed to enter Chechnya itself - a constant demand of the west.

The BBC's Rob Watson, reporting from the summit, said although the gap between Russia and the West over Chechnya remained wide, there was no sign of a breakdown in relations.

In a separate development, Moscow also granted the United Nations refugee agency access to refugees who have fled the fighting.

Chechen town surrenders

Russian troops have continued their push into the breakaway republic of Chechnya, taking another key town without a shot being fired.

Achkhoi-Martan, near the border with Ingushetia, was the second major Chechen town to surrender.

Last week, federal forces entered Chechnya's second city, Gudermes, without opposition.

Local officials were told they would be spared bombing and shelling if they ensured no guerrillas were hiding in the town.

Residents gave up a varied array of weaponry including machine guns and grenade launchers.

Russian troops had surrounded Achkhoi-Martan for days as they pressed towards the Chechen heartland that lies south of the capital, Grozny.

Meanwhile, French news agency AFP reported that some 170 people died in Russian missile strikes on Thursday.

Chechen officials told AFP that 70 died in air strikes on Grozny and another 100 died when five rockets struck Urus-Martan, 20km (12 miles) from the rebel capital.

The death toll could not be independently verified.