Tuesday's explosion at the VMZ Sopot military plant's warehouse near the village of Iganovo was deliberate, Economy Ministry officials have suggested.

Just days after a major explosion at a military depot near the village of Iganovo in March, a second one rocked another warehouse at the site on Tuesday morning. No-one has been wounded, but tens of locals have been evacuated as of 09:20 EEST (07:20 GMT).

Deputy Economy Minister Lyuben Petrov later told NOVA TV that a new "incident" within "such a short lapse of time" raised much doubt.

The ministry's head Bozhidar Lukarski is the principal of the VMZ Sopot plant. Lukarski later echoed Petrov's remarks, adding the blast had occurred on the day before work had to be renewed at the plant following Easter holidays.

Emil Kabaivanov, mayor of the nearby town of Karlovo, said there had been no workers in the depot at the time of the blast. Kabaivanov added two buses had been sent to evacuate locals in Iganovo. He says the version of "sabotage" should not be ruled out.

The Sub-Balkan highway connecting Sofia with the Black Sea city of Burgas is sealed off for traffic as of Tuesday morning in the section passing by Sopot's Anevo neighborhood as police have stepped up security measures following the blast.