By Bethany Bell BBC correspondent in Prague

Prague's historic Old Town district normally throngs with people at this time of year.

Tourists are having to be evacuated from the city centre

Tourist groups and residents would crowd the city's narrow cobbled streets.

But now it seems there are more sandbags than people, as the authorities and residents brace themselves against the rising waters of the swollen Vltava river.

Mila, a tourist from the United States, stood in front of the famous astrological clock in the old town square and threw up her hands in despair.

"I can't find a single tour guide to take me round the city," she said.

"I should have stayed at home", she added, before turning to me and asking if I could perhaps show her around.

Out of bounds

But many of Prague's top tourist attractions are out of bounds.

It's frustrating not to visit places but we've been to see the river... you can't deny it's an exciting time to be here

British tourist

The city's Jewish quarter, with its ancient synagogues, cemetery and the Charles bridge - crowned with its blackened statues of saints - has been closed.

Parts of Mala Strana at the foot of the castle hill have also been evacuated.

Ondrej, a doctor who lives with his parents in Mala Strana, was away when the first flood warnings came.

He has not been able to get back to his flat since then.

"I called my mother on Monday night and she told me everything was OK [but] on Tuesday morning my parents were told to leave," he said.

"They only took a few things with them. They are now staying with relatives and I'm in a flat on the outskirts of town."

"I don't know how my father will manage, he's supposed to go abroad for three weeks but has nothing with him."

But Ondrej, like many of the people wandering around the Old Town square, was philosophical about the chaos happening in his city.

"This is a once-in-a-hundred-years event," he says.

"It happens."

Businesses hit

But shop-keepers and restaurant owners in the Old Town are finding it hard.

Soldiers and volunteers are fighting to save Prague's landmarks

Many shops are closed and chairs from sidewalk cafes are stacked up against the side of buildings.

Khrastina Zlata, the general manager of the Espet Bohemia Crystal shop in the Old Town square, says she is lucky to be open.

"We haven't had electricity since Tuesday afternoon," she said.

"We're running the cash registers and a few lights on an emergency generator [but] most of the other shops on the square have had to close.

"August is usually high season for us but business is right down. We're doing only a third of our normal daily sales," she added.

Disruption

Many of the streets leading off the Old Town square have been cordoned off by police.

Down one otherwise deserted street near the Jewish quarter, soldiers and volunteers struggled with sandbags over the entrance to a cellar.

A huge hose pumped water out into the street.

"The Kafka museum is right there but I can't get to it," said one tourist sadly.

The disruption to tram, road and rail links have caused problems for many visitors here.

David, a tourist who travelled up from Vienna, said their train was diverted.

"Then we spent all afternoon trying to get to our hotel, only to find we couldn't get there, it was closed," he said.

Sally and David, British tourists from Kent said they were hoping more tourist attractions would reopen over the next couple of days.

"It's frustrating not to visit places but we've been to see the river, you can't deny it's an exciting time to be here," they said.