Ammon News - The Guardian - Sixteen people, including the sons of two ministers, have been charged in connection with a sweeping corruption investigation targeting allies of the prime minister, Recep Tayyip Erdoğan.

Suleyman Aslan, the general manager of state-owned Halkbank, was also formally arrested and charged alongside Baris Guler, the son of the interior minister, and Kaan Caglayan, the son of the economy minister, Turkey's state-run news agency reported on Saturday. The son of a third minister and a construction magnate were freed from custody pending trial.

A total of 24 people are now in detention, awaiting trial on corruption allegations, according to the Anadolu Agency. The private Dogan news agency said the ministers' sons and other suspects are accused of taking or facilitating bribes.

The operation began last week, with the detention of scores of people seen as close to Erdogan's government. It has struck at the heart of Turkey's ruling elite.

A court on Saturday ordered the release of 33 others, including the mayor of Istanbul's Fatih district, Mustafa Demir, and the son of Turkey's environment minister.

Dozens of police chiefs have been removed from their posts, accused of abuse of office for keeping the investigation quiet from higher-level officials in security institutions.

Erdoğan has called the investigation a "dirty operation" aimed at undermining his rule and has vowed to go after those who have instigated it.

The inquiry comes amid a power struggle between Erdoğan's government and an influential US-based Muslim cleric, Fetullah Gulen, who has a strong following in Turkey and is believed to have leverage within the country's police force and judiciary.

In his first comments on the case, Gulen has cursed those responsible for a purge of police officers involved in the corruption probe. Gulen's words, invoking God's punishment, raise the stakes in a crisis seen as the biggest challenge to Erdoğan's rule in years.

"Those who don't see the thief but go after those trying to catch the thief, who don't see the murder but try to defame others by accusing innocent people – let God bring fire to their houses, ruin their homes, break their unities," Gulen said, in a recording uploaded to one of his websites on Friday.

The reclusive preacher has lived in the US since 1999.