WARSAW - Russian and Polish investigators struggled yesterday to identify the remains of nearly 100 people killed in a weekend plane crash in which Poland's president and many other top officials perished.

President Lech Kaczynski's coffin returned home on Sunday to a Warsaw plunged into deep mourning and awash with flowers, candles and red and white national flags, but the remains of the 95 other victims were sent to Moscow for identification.

Kaczynski's ageing Polish government Tupolev plane crashed in thick fog near Smolensk airport in Russia on Saturday, reportedly after the pilot ignored traffic controllers' advice not to land.

While the deaths of military leaders and leading opposition figures are a huge blow to the political and military elite, the crash poses no threat to political and economic stability in Poland, a country of 38million people firmly anchored in the European Union and the US-led Nato alliance.

In Poland, the government, not the president, decides policy, though the head of state can veto laws. From the government, only three deputy ministers died.

Financial markets largely shrugged off the crash yesterday, with the zloty currency and stocks flat or slightly firmer.

Acting president Bronislaw Komorowski said he would act quickly to name a new governor of the Polish central bank to replace Slawomir Skrzypek who was also killed.

In Moscow, Russia's health minister Tatyana Golikova said the process of identifying all the bodies would take two to three days.

Her Polish counterpart Ewa Kopacz, visiting Moscow, said: "It's not an easy procedure. In many cases it's only possible to identify the dead with the help of genetic expertise."

The crash has also shocked Russia, Poland's historical enemy and communist-era overlord, which declared a day of mourning. Poland has declared a week of mourning. - Reuters