ATHENS, Greece (AP) — Severe rainstorms eased but floodwaters were still rising in parts of central Greece Friday, while fire department and military helicopters were plucking people from villages inundated by tons of water and mud that have left six dead, six missing and many people clinging to the roofs of their homes.

Flooding triggered by rainstorms also hit neighboring Bulgaria and Turkey, killing a total of 18 people in all three countries since the rains began Tuesday.

In Greece, severe rainstorms that lashed the country turned streams into raging torrents that burst dams, washed away roads and bridges and hurled cars into the sea. Authorities said some areas received twice the average annual rainfall for Athens in the space of just 12 hours.

Evacuation orders were issued for two areas north of the city of Larissa Friday morning, with authorities sending alerts to cell phones in the area warning that the Pineios River had burst its banks. Parts of Larissa, one of Greece's largest cities, were already starting to flood.

“The situation is tragic,” Larissa resident Ioanna Gana told Greece's Open television channel, adding that water levels in her flooded neighborhood were rising “minute by minute.”

Elsewhere, residents of villages left without electricity or drinking water dialed in to Greek television and radio stations, appealing for help and saying people were still trapped on rooftops without food or water.

Between Tuesday and early Friday, the fire department said more than 1,800 people had been rescued and the department had received more than 6,000 calls for help in pumping water from flooded homes and removing fallen trees.

In the Pilion area, residents and tourists were ferried to safety by sea late Thursday as all access roads to some villages were severed. On Thursday alone, a fleet of 10 helicopters airlifted 110 people from the hard-hit areas of Karditsa and Trikala to safety, while dozens more were being rescued by air and boats Friday.

Authorities have deployed swift water rescue specialists and divers as floodwaters rose above 2 meters (6 feet) high in some areas, leaving many houses flooded up to their roofs. Residents of some villages have reported buildings collapsing completely.

The flooding followed on the heels of devastating wildfires that destroyed vast tracts of forest and farmland, burned homes and left more than 20 people dead.