At least 20 killed as sudden floods sweep Istanbul

• Seven women drown on way to work as van submerged
• Stranded motorists clamber on to car roofs to escape torrent

At least 20 people were killed when sudden floods swept Istanbul today, swamping houses, stranding motorists on roads transformed into torrents and drowning seven women on their way to work in a van.

As Turkey's largest city was hit by the heaviest rainfall in 80 years, waters rose more than a metre (3ft) in the Ikitelli district, cutting off the route to the main airport and the motorway to Greece and Bulgaria on the European, or western, side of the sprawling city.

Istanbul is situated on the steep banks of the Bosphorus strait, one of the world's busiest waterways and a major conduit for cargo ships and oil tankers from the Black Sea.

As the waters rose, stranded motorists climbed on to the roofs of their cars, hoping to be rescued. Television footage showed lorries crushed against each other by the floods. Rescue workers put out planks and ladders to help car and lorry drivers reach the safety of bridges and high land.

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

Hikmet Cakmak, Istanbul's deputy governor, described the scene as a "disaster" and said four helicopters and eight boats were sent to help rescue people.

The deaths raised the overall toll in floods that have struck north-western Turkey since Monday to at least 28.

Istanbul firefighters recovered seven bodies at a car park in Ikitelli and seven others were found outside a textiles factory in the district of Halkali nearby. The victims were female factory workers who drowned, trapped inside a van that had just brought them to work. Television footage showed seven bodies covered in white sheets, placed in a row.

Istanbul's Ataturk airport was unaffected by the floods and flights were not interrupted. However, many passengers could not reach the airport or leave it once they arrived.

The Dogan news agency showed footage of a man stranded on top of an overturned van, who plunged into the swirling water and swam towards four men who pulled him out. Elsewhere, a military helicopter lifted about 10 people from the top of a roof. A trail of mud covered some areas as waters later receded in parts of Ikitelli.

Police were deployed to prevent people from looting goods from factories and shops. Even amid the flooding, an Associated Press photographer saw people plundering abandoned vehicles.

"We are saddened by the loss of lives. There are still some people missing and we are searching for them," said the procurement minister, Mustafa Demir. "There is huge damage to infrastructure. We need to be more careful when designing infrastructure and cities."

Rapid population growth as a result of decades of emigration from Turkey's impoverished rural regions has meant that the metropolis of 15 million has developed without adequate infrastructure and poor city planning. Authorities in Istanbul have, in their disaster planning, focused more on earthquakes in a city crossed by a major faultline. Eighteen thousand people were killed by an earthquake that hit north-west Turkey in 1999.