At least one person has frozen to death in Bulgaria's Varna Region after a cold spell with heavy blizzards fell on eastern Bulgaria overnight.

The victim was a homeless man, who has been found dead outside in the major city of Varna.

Another man has died after feeling ill in his car in Staro Oryahovo, and a third sudden death was registered in Varna, but medics could not confirm they were cold-related.

Conditions over much of north-eastern Bulgaria have remained very grave for much of Thursday, with heavy snow drifts blocking most of the roads.

The situation is reported to be the gravest in the Razgrad, Shumen and Dobrich regions, where almost all traffic has been halted, and snow drifts reach 2 m.

Conditions are also heavy in the bordering Ruse and Silistra regions, with snowing expected to continue in much of Bulgaria's north-east.

According to Bulgarian Minister of Infrastructure Lilyana Pavlova, there are no people trapped in their cars on the roads.

The main roads linking the major cities of Varna and Burgas on Bulgaria's Black Sea coast with capital Sofia have been closed.

Roads in the south-eastern regions of Burgas and Kardzhali are also snowed in, say reports.

Many small towns and villages in the remote areas of Kardzhali, Dobrich and Silistra regions have been left without electricity.

Authorities have advised citizens to refrain from traveling, if possible.