ISTANBUL - At least 23 people were killed when floods swept the Turkish city of Istanbul, swamping houses, turning highways into fast-flowing rivers and drowning seven women in a minibus that was taking them to work.

Military helicopters hovered over partially submerged neighborhoods of Turkey's largest city on Wednesday after two days of the heaviest rain in 80 years. Rescue workers, some on boats, put out planks and ladders to help drivers, stranded in fast-flowing waters, reach the safety of bridges and high land.

The worst flooding occurred in low-lying areas in the west of the city, on the European side, where drainage is often poor.

Witnesses said waves of muddy waters pulling cars, trees and debris crashed into homes and buildings early on Wednesday as people were getting up to break their fasting during the holy month of Ramadan.

We heard a crashing sound and then saw the waters coming down carrying cars and debris, said Nuri Bitken, a 42-year-old night guard at a truck garage.

We tried to wake up those who were still asleep in the trucks but some didn't make it. The dead had to be retrieved by boats, Bitken told Reuters.

CNN Turk television showed scenes of white blankets covering the bodies of people found in the western Halkali neighborhood near Ataturk International airport. Airport officials said there was no disruption to flights.

My friend got stuck in the truck after the water rose all at once. The vehicle stopped working after filling with water. We rescued him with a winch, Kamil Coskun told Reuters TV in the Ikitelli district.

Istanbul Governor Muammer Guler said at least 23 people had been killed over two days. Eight were still missing.

Istanbul's ancient district of Sultanahmet, with its mosques, the palaces of the waterfront and Beyoglu's area of narrow streets were largely unaffected.

In the Ikitelli commercial district, residents scrambled for office equipment amid debris. In other parts of the city, people waded chest-high through swamped highways.

HUGE INFRASTRUCTURE DAMAGE

Insurance company Axa Sigorta Deputy General Manager Ali Erlat said damage from the floods could total $70 million-$80 million, the state-run Anatolian news agency reported.

Public Works Minister Mustafa Demir, who toured the worst hit areas, said there was huge damage to infrastructure.

Ali Erdem, chief analyst at the Istanbul Meteorology Department, told Reuters Tuesday's rainfall was the heaviest recorded in the last 80 years.

Prime Minister Tayyip Erdogan, a native of Istanbul, was due to travel to the city on Wednesday.
The bodies of seven women were discovered in Bagcilar, a working-class suburb of Istanbul, on Wednesday. They had drowned in a minibus that was taking them to jobs at a textile factory, Anatolian said.

Istanbul is situated on the steep banks of the Bosphorus strait, which divides Europe from Asia and is one of the world's busiest waterways -- a major conduit for cargo ships and oil tankers passing between the Black Sea and the Mediterranean.

Elsewhere in northwest Turkey, two bridges were demolished by floodwaters on the Bahcekoy-Saray highway.

Istanbul authorities have been more occupied in their disaster planning with making provisions for earthquakes in a city crossed by a major faultline. Eighteen thousand people were killed by a quake that hit northwest Turkey in 1999.

(Additional reporting by Can Sezer, Selcuk Gokoluk in Ankara and Ayla Jean Yackley in Istanbul; writing by Ibon Villelabeitia; Editing by Sonya Hepinstall)