By Ayla Jean Yackley

ISTANBUL (Reuters) - Turkish police have detained at least 24 people working for a pro-Kurdish newspaper since it was banned this week on suspicion of supporting Kurdish militants, the newspaper said.

The detentions bring the number of imprisoned Turkish media workers to 99, based on figures from the European Federation of Journalists (EFJ) media watchdog, making Turkey the world's biggest jailer of journalists.

A government official denied the action against Ozgur Gundem was linked to the state of emergency declared after a failed coup on July 15, but an international media watchdog saw it as part of President Tayyip Erdogan's widespread post-coup purge.

An Istanbul court on Tuesday banned the left-wing newspaper, which has a circulation of 7,500, after ruling it made propaganda for the banned PKK party and acted "as its de facto news outlet," according to the court document.

The PKK is the acronym for the armed Kurdistan Workers Party (PKK), which is considered a terrorist organization by Turkey, the United States and the European Union.

At least 24 people were detained, Ozgur Gundem said according to its website, most of them on Tuesday in the raid on the paper's Istanbul office. Others were detained at their homes. Four journalists covering the raid for other outlets were also detained.

Eren Keskin, a rights activist, lawyer and columnist for the paper whose home was raided, confirmed the arrests.

Turkey has closed more than 130 media outlets since a state of emergency was brought in, stirring concern among Western allies and rights groups about deteriorating press freedoms.

Turkey blames the cleric Fethullah Gulen, who lives in self-imposed exile in Pennsylvania, for the coup in which 240 civilians and security forces, and around 100 coup participants, were killed.

Critics accuse Erdogan of using the purge to crack down on broader dissent. But Turkish officials say they face an internal security threat exposed by the coup plot.

"What just happened at Ozgur Gundem, the historical Kurdish daily in Turkey, is unacceptable. Apparently, the authorities are using the post-coup state of emergency situation to attack all critical voices," said EFJ President Mogens Blicher Bjerregard in a statement.

Among the detainees was Asli Erdogan, a prize-winning novelist, who wrote a column for Ozgur Gundem, according to the paper's website, which was still accessible outside of Turkey.

Authorities seized books at a home belonging to Ragip Zarakolu, a prominent human-rights campaigner and columnist at the Turkish-language daily. Police searched the home of politician Filiz Kocali, who also writes for Ozgur Gundem, and Eren Keskin, a lawyer, told Reuters her home was searched.

Calls to four Ozgur Gundem editors went unanswered. It was not immediately clear if they had been detained.

Ozgur Gundem focuses on the conflict with Kurdish militants in Turkey's southeast and has faced dozens of investigations, fines and the arrest of correspondents since 2014.

The PKK has waged a three-decade insurgency for greater autonomy in the name of Turkey's 15 million Kurds. More than 40,000 people have died in the violence.

(Editing by Patrick Markey and Richard Balmforth)