Four workers were killed and another one was seriously injured in an accident which occurred during landslide rehabilitation in Belgrade on Thursday as a hill came down on them, and it is still unknown whether more workers were cluttered, head of the Interior Ministry's Emergency Management Sector Predrag Maric told Tanjug.

He stated that four workers died in the accident, while another one suffered serious injuries and was transferred to the emergency room.

According to the information we have received so far, his condition is stable, Maric said and added that competent bodies are currently extracting the remains of two workers.

Interior Minister Ivica Dacic told reporters that the accident occurred during landslide rehabilitation and that the exact number of workers engaged on this task is still not known because the company has not released this information.

This is a difficult accident which left many workers dead and the real reason behind the event is yet to be established so that competent bodies could see whether there was any violation of legal regulations and rules in the performance of the works, the minister said.