More than 400 schools, courts in Sarajevo, the National Electoral Commission and a hospital have been forced to evacuate over 48 hours.
Hundreds of schools and public institutions in Bosnia are dealing with a barrage of hoax bomb threats, forcing them to temporarily shut down.
Among the public institutions targeted on Thursday were the National Electoral Commission and several courts in Sarajevo. They all had to evacuate and wait to be told the coast was clear before resuming business.
One of Bosnia's largest hospitals was also targeted on Thursday. Several hundred patients and staff at the university hospital in Banja Luke were instructed to leave due to an email threat.
After searching the hospital, Bosnian police said in a public statement that it had been a false alarm. "It's a despicable attack", hospital director Vlado Djajic told reporters on Thursday.
On Wednesday more than 400 schools were targeted by identical emailed bomb warnings, which claimed attackers planned to "blow up the school" and kill "thousands of Serbian children".
The authorities do not yet know who is behind the threats. Schools and airports in Serbia and Montenegro have also recently experienced an onslaught of fake bomb threats.