MOSCOW - Activists marked the first anniversary of journalist Anna Politkovskaya's slaying Sunday while across town, pro-Kremlin youth thronged a Moscow embankment to celebrate President Vladimir Putin's 55th birthday.

About 1,000 opposition activists paid tribute to Politkovskaya, a Kremlin critic who won international acclaim for her reporting about wartime abuses in Chechnya and whose contract-style killing fueled Western concerns about Russia backsliding on democracy.

Meanwhile some 10,000 members of the youth group Nashi — wearing T-shirts emblazoned with Putin's portrait — chanted "Happy Birthday!" and carried signs bearing slogans such as "Putin is our everything!" and "Putin is our future!" It was a show eerily reminiscent of Soviet-era parades.

The celebrations come as Russia prepares for parliamentary elections in which Putin would top the list of the main pro-Kremlin party — a maneuver that could pave way for his return as prime minister after his second and final presidential term ends next spring.

The Kremlin issued no statement Sunday on Politkovskaya's death and has been dismissive of activists' concerns in the past.

"Politkovskaya's murder has shown that our country is in big trouble," Mikhail Kasyanov, Russia's former premier-turned-opposition leader, said Sunday. "We still hope that people will realize what's going on in the country and come together."

In the days after Politkovskaya's death, Putin said the journalist wielded little influence with her reports and that her killing hurt the Russian government much more than her writing.

Russia's chief prosecutor announced in August that 10 suspects had been arrested. He said her murder had been ordered by someone outside the country to discredit Putin and to destabilize Russia, echoing officials' earlier claims.

"I'm afraid that Politkovskaya's murder will never be solved," said Svetlana Gannushkina, head of the non-governmental Civic Assistance Committee.

Politkovskaya was the 13th journalist slain in a contract-style killing in Russia since Putin took office in 2000, the U.S.-based Committee to Protect Journalists said.

Police on Saturday detained several foreign activists trying to attend a conference commemorating Politkovskaya in the Volga River city of Nizhny Novgorod. They were released after being fined for allegedly violating registration rules, Gannushkina said.

"We are living in a country that isn't free," activist Alexei Permogorov said at the Moscow rally. "And Politkovskaya was fighting for freedom."

But Putin has remained widely popular, thanks to Russia's oil-driven economic boom and his efforts to revive Soviet-era international clout.

Putin is barred from seeking a third consecutive term in the March presidential election. However, he recently said he could return as prime minister — a scenario in which he could eclipse a weakened president.

Putin also said he would top the ticket of the main pro-Kremlin United Russia party in the Dec. 2 parliamentary elections — a move that would likely help it further expand an already sweeping majority in the lower house.

On Sunday, youths marched along the Moscow River chanting "Putin stay with us forever!"

But Putin's former economic adviser Andrei Illarionov, who lost his job in late 2005, warned last week that Putin was building a regime of absolute power. He said Putin's regime could be compared to that of Soviet dictator Josef Stalin or Russian czar Ivan the Terrible.