The series of anonymous bomb threats targeting  shopping center buildings in Bulgaria's Sofia continued on Friday, with the Serdika Center Mall being the latest victim.

The shopping center has been evacuated, local media inform.

This is the fourth time the Serdika Center Mall has been closed over a bomb threat in just three weeks.

On Thursday evening, a bomb threat necessitated the evacuation of The Mall shopping center in Sofia.

Earlier on Thursday, bomb threats also closed down a courthouse in Sofia and two more in Varna.

Another shopping center in Sofia, the Mall of Sofia, was evacuated over a bomb threat several days ago.

Recently, there has been an increased number of bomb threats for shopping centers, courts and schools in Sofia.