Prosecutor General Nikola Filchev told the media last Friday that by May 20, the preliminary investigation into the accident in front of Indigo discotheque should be completed.

Last December, seven children aged between 10 and 14 died in a stampede on the stairs leading to the infamous club.

Filchev was one of the representatives of state institutions involved in the investigation of the case, who were present at a meeting of President Georgi Purvanov with the parents of the dead children.

Other state representatives were Interior Ministry Chief Secretary Boiko Borissov, Council of Ministers Chief Secretary Sevdalin Mavrov, Special Investigation Service Acting Director Roumen Georgiev and Sofia Deputy Mayor Ventseslav Nikolov.

The mothers of the Indigo victims demanded a meeting with the president to ask why no culprits had been arrested. They voiced concerns that someone was covering up the people responsible for the tragedy.

Purvanov said that he would observe the work of all institutions involved in the Indigo accident investigation, without intervening in their operation.

"My impression is that the competent authorities work rather intensively, although there are obviously some things they have missed and maybe have slowed down the pace," Purvanov said.

According to him, any suspicion of an attempt to conceal the truth about the accident was out of question. "There are culprits for what happened there and they will be identified, and the accusations will be supported with arguments," Purvanov said.

"I believe they will be punished."

The president said he would present the issues related to the tragedy at the sitting of the National Security Consultative Council on Tuesday. A governmental programme is to be considered envisaging measures for children's security.

All representatives of state institutions who attended the meeting adopted a joint position that it is necessary to urgently amend some laws to prevent any repetition of such accidents, Plamen Kirov, legal adviser to the president, said after the meeting.

"I am thinking of addressing a letter to Parliament and the Government, listing the laws and normative acts which need a speedy amendment," Purvanov said later on Friday.

The participants in the meeting agreed to work out a comprehensive programme for protecting the health and lives of Bulgarian children, Kirov said.

"We must give a very clear sign to the bandits that there will be retribution, and to all those who have decided that they can go unpunished making money at the expense of the health and the lives of our children," Purvanov said.

The president will once again receive the mothers of the teenagers in a month to acquaint them with the developments in the investigation.