Thousands of Turks took to the streets in Istanbul on Wednesday to demand the government resign over an alleged leaked recording of Turkish Prime Minister Recep Tayip Erdogan and his son, discussing how to hide large sums of cash amid an ongoing graft probe.

Some 5,000 people gathered in Istanbul's busiest street Istiklal in a rally organized by the main opposition Republican People's Party (CHP), asking the government to submit resignation.

CHP's leader Kemal Kilicdaroglu has claimed that the recording is genuine, saying his party had it examined by voice experts.

During the rally, the crowd shouted "The thieves are here," and symbolically threw 30 million fake euros to the streets.

"My father is a retired employee and he earns 800 Turkish liras (about 380 US dollars)," deputy head of CHP's Istanbul youth branch Firat Erdogan told Xinhua. "I ask my father, 'I have only 20 liras in my pocket until the end of the week... (But) Prime Minister's son asks his father about 30 million euros left at home. What will I do?" he said, referring to the alleged conversation between Erdogan and his son in the audio recordings.

Thousands of riot police have been deployed in iconic Taksim Square and nearby Gezi park in downtown Istanbul.

This is the second protest in a week after the recordings were leaked, which sent shockwaves through the country.

Thousands of people staged protests in 11 cities on Tuesday evening, including the capital Ankara, Istanbul, Izmir, Antalya and Antakya.

The audio recordings disclosed on the internet on late Monday suggesting the Turkish prime minister ordering his son Bilal Erdogan to dispose vast amount of cash just after a graft probe launched on Dec. 17 when police raided sons of three ministers, local media reported.

Erdogan has rejected the allegations, labeling the leaked recordings as "fake."

The leaked recording is "vile attack" that won't go unpunished, he said on Tuesday addressing his lawmakers at a parliament session.

He described the recordings as part of "efforts to overthrow the government," saying: "This coup attempt will not remain unanswered."