By Alexei Anishchuk
YEREVAN (Reuters) - Hundreds of people marched through the capital of Armenia on Monday to denounce visiting Russian President Vladimir Putin and protest against plans to join a Moscow-led customs union.
Some of the estimated crowd of 500 in central Yerevan held up banners declaring "Putin, go home" or "No to the USSR", a reference to the Russian leader's efforts to bind former Soviet republics together more closely in economic and security alliances.
Police in Yerevan said they detained 110 protesters, the local news agency Arminfo reported.
Putin flew to the South Caucasus country for talks on its decision in September to join Russia, Belarus and Kazakhstan in a Customs Union, which he touted as having already brought "tangible dividends."
The rally in Yerevan followed much larger protests in Ukraine after it abandoned a trade pact with the European Union last week to rebuild economic ties with Russia instead.
Putin described the Ukrainian protesters as "very well prepared and trained militant groups" engaged in an attempt to shake its legitimate rulers, He hinted that they had been trained by outside actors, an accusation he made against participants in Ukraine's "Orange revolution" which overturned a stolen election nine years ago.
Kremlin critics in the West accuse Putin of putting pressure on Ukraine, Armenia and other ex-Soviet republics to reject deals that would increase their integration with the EU.
Demonstrators in Yerevan marched to President Serzh Sarksyan's administration to hand over a letter urging the government to renounce its decision to join the Customs Union.
Putin has made clear Moscow wants to increase its influence in the strategic region sandwiched between Russia, Turkey, Iran and the oil and gas deposits of the Caspian Sea basin.
"We are going to strengthen our position in the South Caucasus, drawing on the best of what we have inherited from ancestors and good relations with all countries in the region," Putin told a Russian-Armenian regional forum.
"Participation in the Customs Union ... already is bringing Russia, Kazakhstan and Belarus tangible dividends."
Putin said that under an agreement signed Monday to regulate natural gas deliveries to Armenia, Moscow will forgo 30 percent export duties. Russia will supply Armenia gas at a price of $189 per 1,000 cubic meters, he said.
Russian state gas export monopoly Gazprom also said on Monday it would take over full ownership of its subsidiary ArmRosgazprom, by acquiring the remaining 20 percent of shares from Armenia.
Russia is the biggest foreign investor in Armenia and its largest trading partner. Bilateral trade grew 22 percent to $1.2 billion last year. Most trade has been imports to Armenia.
In 2010 Russia extended its lease on a military base in the landlocked, resource-poor nation of 3.2 million until 2044, ensuring it maintains a firm foothold in the South Caucasus.
The region includes Azerbaijan, which has been embroiled in a territorial dispute with Armenia since the Soviet collapse, and Georgia, with which Russia fought a five-day war in 2008.
(Reporting by Hasmik Mrktchyan and Alexei Anishchuk; Writing by Steve Gutterman and Alissa de Carbonnel; Editing by Timothy Heritage/Mark Heinrich)