Ethnic Russians in Latvia held a huge rally in defence of their language rights as the ex-Soviet nation formally joined the EU with nine other states.
Saturday's mass protest passed off peacefully
At least 20,000 marched peacefully through Riga wearing the label "alien" in English to protest at a law curbing the use of Russian in education.
All schools must teach mainly in Latvian under the EU-approved law.
Russian-speakers make up almost a third of Latvia's population and less than half have been given citizenship.
"We want the world to hear us, but not in the Latvian language," Daria Aozlova, an 18-year-old student, told AP news agency.
"We are not celebrating [EU entry] today, because we are angry. We want to learn in our language."
Another demonstrator, 49-year-old businessman Andrei Merkushev, said the demonstration was not anti-EU.
"The EU celebration is my celebration too but I had to choose and this is more important to me," he said.
'Backed by Europe'
The demonstrators, some of whom had arrived in the capital by bus specially for the occasion, sang the anthem of the Russian-language movement, a version of Pink Floyd's Another Brick In The Wall.
RUSSIANS IN LATVIA
29.6% of current population (2001 figures)
34.8% under Soviet rule (1989)
10.5% under the first independent Latvian Republic (1918-1940)
Just over 10% at the height of the Russian Empire (1897)
sources: Latvian Institute, CIA Factbook
They gathered at the Soviet-era Victory Monument, which marks the defeat of Nazi Germany but is seen by many Latvians as a symbol of the start of Soviet oppression.
Recent parades by Latvia's Waffen SS veterans have added to the country's ethnic tensions.
Under the education reform passed in February, at least 60% of classes must be taught in Latvian in public schools, including those catering for Russophones, come the new school year in September.
Only on Friday, President Vaira Vike-Freiberga went on Latvian radio to defend the new language law and accuse Russophone protesters of seeking to discredit the country on its day of EU entry.
"Europe has weighed us, measured us, assessed us," she said.
"Our laws, in every respect, from every side, have been examined and found to be compatible with human rights. Europe is not going to reject us, whether or not our schoolchildren protest in the streets."