Around 2.7 million people are eligible to participate in both a presidential election and a referendum on joining the EU according to figures from the president's office.

The referendum asks people to vote yes or no on enshrining the aim of EU membership in the country's constitution.

One of the poorest countries in Europe, Moldova applied to join the EU after Russia invaded Ukraine.

Moscow isn't keen to give up influence in the former soviet state strategically positioned next to Ukraine and the Black Sea.

Russia has nearly 1,500 troops stationed in Transnistria, a region run by pro-Russian separatists who broke away from the control of the Chisinau government in a brief war in the 1990s.

Read more: Moldovans divided over EU referendum

Moldova has faced a cut in Russian natural gas following the war in Ukraine, causing high inflation and prompting the government to seek out alternative sources of energy.

Earlier this month, Moldovan police seized money and documents they allege were linked to Russian-backed groups trying to meddle in Sunday's vote.

They found more than 130,000 people had been bribed to vote "No" in the referendum and uncovered a programme in which hundreds of Moldovan citizens were brought to Russia to undergo training to stage riots and civil unrest.

The Kremlin denies any involvement and accuses critics of spreading "Russia-phobia".

In the presidential election, pro-Western incumbent Maia Sandu is looking for a second term.

Her opponents include Alexandr Stoianoglo, a former prosecutor backed by the traditionally pro-Russian Party of Socialists, and Renato Usatil, a former mayor of the northern city of Balti.

Around 3 million people live in the small southeast European republic.

It has a Romanian-speaking majority and a large Russian-speaking minority, and since the break-up of the Soviet Union has alternated between pro-Western and pro-Russian courses.