Protesters took to the streets across Turkey on Tuesday, after audio recordings purportedly of Turkish Prime Minister Recep Tayyip Erdogan ordering his son to dispose of vast amounts of cash amid a graft probe surfaced and went viral on the Internet.

Thousands of people demonstrated in 11 cities, including Ankara and Istanbul, shouting anti-government and anti-Erdogan slogans, according to China’s Xinhua news agency.

Police in the capital fired tear gas and water cannons to disperse the crowd that chanted, “The government resigns” and “Thief Erdogan.”

In Istanbul, protests were reportedly held at 10 locations, with the biggest demonstration in the district of Kadikoy, where some 5,000 people marched to the district center, carrying banners reading, “Where are the thieves?” and “You will answer to the people.”

Protests were also held in the cities of Izmir, Antalya, Antakya, Samsun, Trabzon, Eskisehir, Kocaeli, Bursa and Canakkale, according to Xinhua. Clashes between riot police and the crowds were reported in Istanbul, Bursa and Eskisehir.

A chief prosecutor’s office on Tuesday initiated an investigation into the audio recordings in question, Turkish state-run media reported, as opposition parties demanded that the government resign.

Erdogan met with Turkey’s intelligence chief shortly after voice recordings of two people — alleged to be Erdogan and his son — circulated on the Internet on Monday.

A protester waves a flag as another fires a slingshot from behind trash bins as they clash with riot police during an anti-government protest in Istanbul, Turkey, on February 25, 2014 (photo credit: Gurcan Ozturk/AFP)

A protester waves a flag as another fires a slingshot from behind trash bins as they clash with riot police during an anti-government protest in Istanbul, Turkey, on February 25, 2014 (photo credit: Gurcan Ozturk/AFP)

The voices were heard discussing means of getting rid of large amounts of money from an undisclosed residence.

A statement issued by Erdogan’s office later said the tapes were fabricated and that legal action would be taken against those responsible.

It was not clear if the probe by Ankara’s chief prosecutor was to determine the recordings’ authenticity or whether they pointed to a possible criminal act by the prime minister.

Earlier on Tuesday, Devlet Bahceli, the leader of Turkey’s far-right Nationalist Action Party, called the recordings “mind-blowing” and urged prosecutors and other judicial bodies to intervene.

The Republican People’s Party, Turkey’s main opposition, claimed to have verified the authenticity of the recordings through “three or four channels” and called on Erdogan to either resign or “flee (Turkey) by helicopter.”

Bilal Erdogan (photo credit: YouTube screenshot)

Bilal Erdogan (photo credit: YouTube screenshot)

On Tuesday, Erdogan lashed out at Turkish and foreign enemies he claimed were conspiring to bring his government down and again charged that the tapes were fabricated.

“This is a treacherous act against the prime minister of Turkey,” he said.

The audio recordings reportedly took place on December 17, when three cabinet ministers’ sons were detained in the police corruption and bribery probe.

The government said the investigations were orchestrated by followers of a moderate Islamic movement led by US-based cleric Fethullah Gulen. Gulen denies involvement.

Erdogan says the group wants to discredit the government before local elections in March and a presidential election in August.

The Associated Press contributed to this report.