Severe flooding in Italy and France have left 12 dead so far, but rescuers are also finding corpses long dead that washed down to shore.

Four deaths have been confirmed in France, while eight have been confirmed in Italy, according to an article published Tuesday by the Associated Press.

20 people are reportedly still missing, a spokeswoman for the Alpes-Maritimes regional administration told the AP. Over 600 rescuers have been searching for the people still missing in the region, according to the outlet.

The corpses were found on the Italian coastline and it is unclear where they came from or how many were found. The bodies were identified as corpses due to the significant decomposition, according to the spokeswoman. Forensic police are reportedly working to identify the bodies.

Roads were still blocked by debris Tuesday. The situation has been described as “catastrophic” and a “phenomenal disaster.”

“It’s a catastrophic situation, this has not happened in a thousand years,” Georges Pomarede, a retired police officer, told the outlet. “All of that is gone, no more campground, no stadium, no more swimming pool, no more shops, a hotel is gone, … entire houses swallowed by the floods. It’s a phenomenal disaster.”