Thousands of people have gathered in the center of Moldova’s capital ahead of the 100th anniversary of the unification of Bessarabia and Romania.

The March 25 event at Chisinau’s Great National Assembly Square was organized by several groups from Moldova, Romania, and the diaspora that are calling for Moldova's reunification with Romania.

Organizers estimated that about 100,000 people attended the so-called Great Centennial Assembly, while police put the figure at 7,000.

The gathering is meant to mark 100 years since the Russian Empire’s former province of Bessarabia -- which covers parts of today’s Moldova and Ukraine -- was unified with the Kingdom of Romania on March 27, 1918.

Later on, during World War II, Bessarabia was incorporated into the U.S.S.R., with most of its territory becoming the Soviet republic of Moldova.

And when the Soviet Union collapsed in 1991, it became independent under the name Moldova.

The country is now split between a Romanian-speaking majority and the Russian-speaking separatist region of Transdniester, which declared independence from Moldova in the early 1990s.

During the rally in Chisinau, organizers read a "declaration of union" that was adopted by the participants who chanted “reunion.”

Former Romanian President Traian Basescu and the ex-mayor of Chisinau, Dorin Chirtoaca, were among the speakers.

Basescu said the integration of Moldova with Romania was the “only way" for the two countries to regain their dignity.

Backers of reunification say it would be the way forward for corruption-ridden Moldova to move forward and join the European Union. Romania is already a member of the bloc.

The Romanian parliament is set to hold an event on March 27 to mark 100 years since the unification of Bessarabia with Romania, while no official celebrations were planned in Moldova.

The country’s pro-Moscow president, Igor Dodon, has rejected calls for reunification as a threat to national security.

In a recent interview with RFE/RL, he said Romania might become “Moldova’s enemy No.1” if it continues what he called its aggressive unionist path.

Moldovan forces and Moscow-backed Transdniester fought a short war in 1992 over fears that newly independent Moldova would seek reunification with neighboring Romania.

The conflict ended with a cease-fire agreement after Russian troops in the region intervened on the side of the separatists. Russia has some 1,500 troops stationed in the breakaway region. Transdniester's independence is recognized by no country, but Moscow has been unofficially backing the separatist regime.