Thousands of people defied the rain in the German capital, Berlin, on Saturday to protest the rising cost of housing amid rampant gentrification. Berlin has the fastest-rising property prices in the world, according to a report published this week.

"This isn't a demonstration; we're all just going to an apartment viewing," read one ironic banner as the march moved through Berlin's Kreuzberg district, once a derelict part of West Berlin largely cut off by the Wall, now a bustling neighborhood of immigrants, students and hip cafes — an identity that is being threatened as decades-long residents are being priced out of their dwellings.

According to a study published by real estate consultancy Knight Frank on Thursday, prices in Berlin rocketed by 20.5 percent in 2017 alone.

The firm's "Global Residential Cities Index" showed that while most housing prices dropped around the world in recent years, Berlin was one of only 12 cities to have had a price growth of over 20 percent in 2016.

Overall, prices have increased by 120 percent since 2004, as low unemployment and foreign investment have buoyed the city. However, Germany's central bank believes that properties may be overvalued by as much as 35 percent in Berlin. Of the 1.9 million affordable homes Germany is lacking, 310,000 are needed in Berlin.

About 182 different Berlin-based renter initiatives took part in Saturday's demonstration, affectionately nicknamed the "Renting Nonsense" protest. Initially, organizers expected about 4,000 participants to show up — but as the sun came out later in the day, witnesses said it looked like more than 10,000 had arrived to call on the Berlin Senate, the executive body governing the city and state of Berlin, to do something about the dramatic increase in the cost of living.

But the Senate has contested the numbers put forward by some recent studies, saying that rents have risen only by 1.4 percent. Berlin's housing secretary, Sebastian Scheel of the Left party, was quoted by the local Morgenpost as saying that higher prices were necessary "to invest continuously in new residential construction and maintenance."