Reports of vote-buying and controlled voting ahead of the 25 October presidential and vice-presidential election are down compared with past votes, interior minister Ivan Demerdzhiev says.

"Right now we don't have as many reports and signs of vote-buying and controlled voting," he said, adding that this doesn't mean police are paying less attention or doing less work.

Some election-related crime is moving online, Demerdzhiev said, so police are watching and acting there too.

The prosecution, the interior ministry, the state security agency and the election commission met today to coordinate how to keep the vote running smoothly and within the law. The minister said extra attention is going to the online space and to breaches of election law.

Demerdzhiev also gave details on the official welcome for the remains of Tsar Samuil. The ceremony starts on 3 October at 12:30pm at Knyaz Alexander I Square, in front of the Princely Palace in Sofia, after which the remains will be laid to rest at St Sofia Church.

The institutions taking part met earlier today with the prime minister. Police will step up security and keep public order on Saturday.

"We're witnessing something without precedent — the remains of a Bulgarian tsar are coming home to be laid in the land of his ancestors," Demerdzhiev said, urging people to attend the ceremony and pay their respects to the ruler.

The minister said it's hard to grasp right now just how important it is to bring the remains back. Work on this has gone on for years, and the remains are coming home thanks to cooperation between Bulgaria and Greece and diplomatic efforts.