"The death toll has increased to 16," a spokesperson for the regional office of the interior ministry told journalists, adding that there were no children among the casualties.
Earlier, Ulyanovsk Governor Alexey Russkikh, said that four people, three men and a woman, had been hospitalized in critical condition and were being treated.
Local emergency services said that the causalities are believed to include citizens of Kazakhstan.
Kazakh Foreign Ministry spokesman Aibek Smadiyarov told Sputnik that there was no preliminary data on Kazakh casualties in the crash, citing the Russian ministry for emergency situations (EMERCOM).
"According to preliminary data of the EMERCOM headquarters in the Ulyanovsk Region, there are no citizens of Kazakhstan among the casualties in the road accident in the Ulyanovsk Region," Smadiyarov said.