In a message to Bulgarian Economy Minister Peter Dimitrov, Serbian Trade and Services Minister Slobodan Milosavlevic insists that the persons responsible for blasts outside two Serbian-owned supermarkets in Bulgaria, be tracked down and punished, Tanjug reported Friday.

The explosions were caused by make-shift bombs and occurred in the small hours on Thursday outside two stores of the Piccadilly supermarket chain in the Bulgarian Black Sea city of Varna. No one was hurt.

Last September the Piccadilly chain was acquired by the Serbian-registered Delta Max Group. The Varna-based Bolyari EAD holds a minority share of 15 per cent.

The supermarket owners and managers told police they have never received any threats. Police say that the blasts seem to have been meant to threaten somebody rather than to cause serious damage.

In his message to his Bulgarian counterpart Milosavlevic calls for protection of the assets of Serbian companies operating in Bulgaria. He also says that the explosions caused concern among the Serbian public. A large number of Bulgarian companies work and invest in Serbia and they have never had any problems with their security, he reportedly said.

Further on, he asks to be regularly updated of the course of the investigation into the explosion and of any measures that would be taken to protect the property of Serbian companies.