About 150 protesters denouncing the Group of Eight summit faced off with police Saturday, but officers in riot gear blocked them from leaving the isolated stadium where the government had confined them.

In a separate protest, some 250 people attended a Communist Party rally downtown. Police said 15 young activists were detained on their way to that gathering.

The detentions came after police and the youngsters shoved each other. Women screamed. Officers carried one protester to a police bus by the arms and legs.

Despite the confrontations and detentions, Saturday's protests were smaller and less disruptive than those at previous G-8 summits, in which tens of thousands of people rallied and some groups smashed windows and clashed with police.

The Kremlin's determination to keep a lid on demonstrations during the summit underlined Western criticism of Russia for intolerance of opposition.

Authorities told protesters they could gather only at a stadium about 9 miles from the city center and rejected their request for permission to march.

More than 200 people were detained or prevented from traveling here for the "counter summit," organizers said.

Chanting "Russia is not a jail. No to G-8!" about 150 people marched to the tall metal fencing about 300 feet from the stadium, where human rights activist Lev Ponomarev urged police to let them go further.

"I guarantee there are no radicals," he said.

Police refused; a cordon of about 40 riot police stood just outside the gates.

Some protesters shook the fencing and others sat cross-legged, but the crowd began to thin after an hour. Most returned to the stadium, where an outdoor kitchen served soup, tea and rice.

Despite being unable to take their protest to the streets, participants said the gathering was useful nonetheless.

"I can see now that it's not just a dictatorship, it's a crazy one," Garret Mullan, a member of Socialist Party of Ireland, said of the scene at the stadium.

In a private meeting, President Bush said he told Russian President Vladimir Putin that Americans would like to see more freedom in Russia.

But, Bush said "he also explained to me that he doesn't want anybody telling him how to run his government."

Vladimir Soloveichik, an organizer of the stadium event, suggested the U.S. should put more pressure on Russia.

"I don't want to give advice to the American government but, in my view, people can't be free if they support a dictatorial regime in another county," he said.

Mikhail Kasyanov, a former prime minister under Putin and a rising opposition figure, said opponents would like to hear some kind of disagreement with Putin's policies, "and would like to hear this from leaders of other G-8 countries."

G-8 leaders were expected to raise the issue at the summit, though Russia would rather not hear it.

"Nobody knows better than us how we can strengthen our own nation," Putin said.

The Communist demonstration attracted mostly older people, who waved red flags. Speaker after speaker berate the G-8 and musicians sang nostalgic, Soviet-era songs.

"Parasites, our own and foreign ones, should clear out of Russia," said one banner.