Although they did not attract more than a few hundred people each, latest protests over the fuel prices drew alarmed reactions from the governing coalition on Monday.
Bulgarians from over 30 towns and cities took to the streets and blocked roads on Sunday to protest over rising fuel prices and changes to vehicle transport legislation.
Professor of Sofia University and Associate Professor of Civil Law Christian Takov has died, his family said.
"On July 11, at age 51, Christian Takov has died. He was a person with a huge soul, heart, power and intellect, who remained unrelenting to injustice, we all who loved him are mourning, the date of the service will be specified" clarified a message from his relatives.
Bulgaria's outgoing Prime Minister Boyko Borisov has returned the mandate to form a government on Friday after receiving it from President Rosen Plevneliev.
Borisov has only kept the mandate for less than a minute.
He has made clear his party, GERB, which is the biggest in Parliament, will not seek a new cabinet within the current legislature.
As Bulgarians are heading to the polls on Sunday, they will vote for President based on what they saw and heard in five weeks of campaigning.
Support from parties and candidates who fared well in the election's first round, however, may also play a part in this decision as some of these have endorsed or indicated preference for either of the candidates.
The independent candidate supported by BSP for President Rumen Radev receives the vote of 49.6% of the voters on the eve of the second round of elections on Sunday.
A total of 39.1% of voters will vote for GERB's candidate Tsetska Tsacheva, showed data of Alpha Research. 11.3% of the participants of the survey stated that they will not vote.