Over 5,000 people gathered in Istanbul’s Kadikoy district and some 1,000 in the Besiktas district Wednesday night to show their anger over the graft scandal, Xinhua news agency reports.

Protesters have also gathered in the capital of Ankara, as well as in Izmir and other cities. Ruptly news agency says hundreds took to the streets of Istanbul.

Police in Istanbul have fired tear gas to disperse the demonstrators. At least four people have been arrested, according to Firat news agency.

Late on Wednesday, Erdogan announced a major cabinet reshuffle, replacing 10 key ministers. This came soon after the resignation of interior, economy, and environment ministers over a high profile corruption investigation. Resigned Environment Minister Erdogan Bayraktar turned against the Turkish leader, urging him to step down.

The scandal and ensuing feud between Erdogan and the judiciary have reignited anti-government protests against Erdogan’s 11-year rule within the past week.

The protesters rallying in Istanbul have shouted slogans such as "Three ministers' resignation is not enough, the whole government should resign," as well as " corruption is everywhere” and "resistance is everywhere," Xinhua reported.

More than 10 political parties and organizations have called for the protest.

The graft scandal poses an unprecedented challenge to his 11-year rule, which survived a massive anti-government demonstration that swept the nation in mid-2013.

Dozens of people have been arrested in the ongoing corruption investigation, including the head of state-run Halkbank. The government responded by purging police investigators describing the probe as a “dirty game.” Erdogan claimed it was a plot by foreign and other anti-government forces ahead of the March local elections.

According to Hurriyet newspaper, up to 550 police officers - including senior commanders - have been dismissed nationwide in the past week by now former Interior Minister Muammer Guler.

NTJ/NJF