Bulgaria is considering whether to seek compensation from Romania for the cyanide spill contaminating the river Danube.

It said Romanian officials had failed to provide adequate information about the extent of the spill when it occurred at a gold mine in Romania last month.

The Bulgarian authorities have banned fishing on the Danube and using river water for irrigation or household needs.

According to the country's Environment Minister, Evdokia Maneva, cyanide levels in Bulgaria's stretch of the Danube were 40% above internationally-accepted levels.

She said Bulgaria would raise the issue with an international commission of Danube countries and with the European Union.

Lawsuits

In Hungary, green groups held a candle-lit procession to the parliament building on Sunday, with some 500 demonstrators calling for Europe-wide co-operation on environmental disasters.

So far, river systems across four countries have been poisoned by the spill.

Hungary has been worst affected, with all marine life feared dead in two of its river systems.

The government says it is considering a series of lawsuits against the Romanian- and Australian-owned mine, as well as the Australian parent company and possibly the Romanian government.

The first lawsuits could be filed this week.