CAIRO- Egyptian security forces detained prominent blogger and journalist Wael Abbas on Wednesday, two security sources and his lawyer said, the latest activist to be arrested in what rights groups say is a campaign to silence government critics.

Abbas, an award-winning journalist and rights activist, was taken from his home early on Wednesday and his whereabouts are unknown, his lawyer Gamal Eid said on his Twitter account.

An Interior Ministry official said he was checking the report. Two security sources, who declined to be identified, confirmed Abbas had been detained but gave no details on the reasons.

The Arab Network for Human Rights Information (ANHRI) said that armed police raided Abbas's home at dawn, without presenting an arrest warrant, blind-folded him and took him in his pyjamas to an unknown location.

In a message on his Twitter account, Eid said Abbas had been "kidnapped, not arrested."

Abbas first became known in activist circles after posting videos showing police brutality. One such video, published in 2006, caused such uproar that it prompted an investigation resulting in a rare conviction of two policemen.

Abbas was awarded International Center for Journalists' Knight International Journalism Award in 2007.

Rights groups accuse the government of President Abdel Fattah al-Sisi of a sweeping crackdown on dissent which they say is the worst ever for Egypt.

Since 2013 when Sisi took power, thousands of Islamist opponents, as well as scores of liberal activists and journalists have been imprisoned by the authorities.

Sisi, who ousted President Mohamed Mursi of the Muslim Brotherhood after mass protests against his rule, denies that there are political prisoners in Egypt.

Last week, Egypt's state security prosecutor ordered Haitham Mohamedeen, a leftist lawyer, and Shady Ghazaly Harb, a leading opposition figure during the 2011 uprising, to be detained for 15 days and investigated for a terrorist organization.

On Tuesday a court sentenced journalist and researcher Ismail al-Iskandarani to 10 years in prison on charges of publishing false news and military secrets for his work on an ongoing army campaign against militants in the Sinai Peninsula, his lawyer said.

Amnesty International condemned the sentencing.

In an unprecedented move, authorities arrested a former military chief in January before he could challenge Sisi in a March presidential election, which he ended up.

"Egyptian authorities continue their security campaign to silence all critical voices and fabricate cases against them in order to avenge and to silence them," the ANHRI statement said.

(Editing by Raissa Kasolowsky) ((amina.ismail@thomsonreuters.com; +20 2 2394 8114;))