Ukraine has made public secret archives concerning the Soviet Union's armed intervention against Czechoslovakia's 1968 Prague Spring pro-democracy movement, according to a government statement Thursday, DPA reported.

Officers from Ukraine's national intelligence agency, the SBU, turned to the government of the Czech Republic 311 formerly classified documents from the period, according to a SBU statement.

The more than 1,000 pages of archival papers, transferred to the Czech government in electronic format, document Soviet planning, intelligence, and decision-making concerning an August 1968 Warsaw Pact intervention against Czechoslovak political liberalisation.

The Soviet leadership was well aware a majority of the Czechoslovakian population was likely to oppose an invasion by Warsaw Pact tanks and infantry, and some Czechs and Slovaks might fight to defend a pro-democracy movement in the country, according to the newly-released archives.

Soviet propaganda of the time asserted most Czechoslovak citizens welcomed an intervention bringing order to the country, and that persons resisting Warsaw Pact forces were anarchists or foreign agents.

More than 100 Czech and Slovak citizens died, and more than 500 were injured in fighting against close to 200,000 Soviet, Polish, Hungarian, Bulgarian, and East German soldiers invading Czechoslovakia.

Ukraine's government since 2005 has moved quickly to declassify substantial portions of Soviet-era archives, as part of a state programme aimed at promoting the study of modern history, and of publicising aspects of Soviet-era history previously masked by propaganda.

Neighbouring Russia continues to hold most its Soviet-era archives under tight control.