Devecser, Hungary (CNN) -- The death toll from a toxic sludge spill in Hungary rose to seven Friday after an additional body was found, according to a spokeswoman for Hungary's emergency services department.
The deadly red sludge came from an aluminum plant reservoir that burst Monday, inundating three villages, the official news agency MTI reported.
Water test results made public earlier in the day, however, indicated that the sludge may not harm the Danube River -- news eagerly embraced by leaders from neighboring countries.
Romanian Environment Minister Laszlo Borbely said experts believe the sludge now poses no imminent danger for his country or neighboring Bulgaria. He said he trusts Hungary is disseminating accurate information about the spill.
"The international community is watching them," Borbely told CNN affiliate PRO TV Romania. "Unfortunately, what happened in Hungary is a unique catastrophe."
He added that scientists are monitoring the waters where the Danube enters western Romania.
Hungary has activated the European Union's Civil Protection Mechanism for urgent international assistance, the EU announced Friday. It means Hungary can tap into the resources of 31 participating European nations to respond to the disaster.
The sludge reached the Danube on Thursday as emergency officials worked to contain as much of it as possible.
"It is a huge tragedy for the whole country," Anna Nagy, a Hungarian Disaster Management official, said Thursday. "We love the Danube, we're very proud of the Danube, and we tried to protect it."
"I hope we can save the life in the river," she said.
Hungarian officials have said they need time to calculate the cost of the disaster, noting that the government's first response has been to try to save lives and clean homes.
Emergency workers have been pouring plaster and fertilizers on the sludge in hopes that it will counter its alkalinity.
The exact chemical composition of the sludge has not been revealed, but aluminum processing normally involves compounds that include cyanide, cadmium and chromium.
The environmental disaster occurred nearly 100 miles west of Budapest, near the town of Ajka. The list of victims includes two children, ages 1 and 3; an elderly woman; a 35-year-old man whose SUV overturned in the sludge; and a man who died in a hospital.
About 250 people have been evacuated from their homes, according to Gyorgyi Tottos, the Hungarian emergency services spokeswoman. More than 900 people and 130 vehicles are being used in rescue operations, a report from Hungary's Interior Ministry said.
The reservoir has been repaired and the flow from the pool halted, but the material that flowed out of the reservoir continues to pose a threat. Also, as the sludge dries, dust can develop, the report noted. Some workers involved in the damage control efforts may need filtering masks, it said.
The aluminum factory has said it will pay for the victims' funerals. It has property and liability insurance, insurer Allianz Hungaria Biztosito told CNN, but it would not say how much.
Residents were advised not to eat produce from gardens that were covered when the dam burst.
It was not clear when residents evacuated from affected areas in the villages of Kolontar, Devecser and Somlovasarhely would be able to return home.
The long-term consequences of the leak were also unclear. A state of emergency has been declared in three counties, the State Secretariat of Governmental Communications said. In some villages, police with guns patrolled to keep looters at bay.
The latest Danube readings taken by investigators indicate the pH -- or acidity -- level is 8.5, lower than the original reading of 13, but still slightly above normal, Tottos said.
Tottos said the 8.5 pH is not dangerous and can sustain life; pH readings range from 0 to 14. Levels lower than 7 characterize acids, and levels higher than 7 denote bases. Highly acidic or highly basic water can harm living things.
Investigators found some dead fish in the water, but Tottos said the fish may have died upstream, before they reached the Danube.
The 8.5 pH level and fast-moving currents make officials optimistic that a natural disaster can be avoided, she said.
She added that the pH level will normalize by the time the Danube -- Europe's second-longest river -- reaches countries downstream, which include Croatia, Serbia, Bulgaria, Romania and Ukraine.
CNN's Antonia Mortensen, Nic Robertson, Tommy Evans, Jim Boulden and Eileen Hsieh, and journalist Fanny Facsar contributed to this report.