Bahrain Mirror (AP): Bahraini police detained a prominent activist during a raid on his home early on Monday morning, rights groups and the activist's family said, part of a wide crackdown on dissent more than five years after the Arab Spring.

It wasn't immediately clear why authorities detained Nabeel Rajab, the president of the Bahrain Center for Human Rights. However, his detention comes after Zainab al-Khawaja, another prominent activist, fled the island nation for Denmark in recent days over fears of being imprisoned again.

Police seized electronic devices and other items from Rajab's home as they detained him, according to the Bahrain Institute for Rights and Democracy. Rajab's wife, Sumayia, also confirmed his arrest and said on Twitter that their home was searched.

The raid was not immediately reported by the state-run Bahrain News Agency. Officials with Bahraini police and the Interior Ministry did not respond to a request for comment.

Rajab helped lead protests during Bahrain's 2011 demonstrations as the island's majority Shiite population and others demanded more political freedoms from its Sunni rulers. Bahrain, home to the U.S. Navy's 5th Fleet, crushed the protests with the help of troops from Saudi Arabia and the United Arab Emirates.

In the time since, the island has faced low-level unrest, protests and attacks on police. Other prominent opposition figures and human-rights activists remain imprisoned, while some have had their citizenship stripped by the government and been deported.

Rajab has been detained by authorities several times.

In 2015, King Hamad bin Isa Al Khalifa pardoned Rajab over health concerns following imprisonment for three months on charges related to comments he made online criticizing the treatment of political prisoners at a prison in the Arab Gulf country.

Rajab at the time also faced a six-month sentence for insulting defense and interior ministries on Twitter when he alleged that Bahrain's security institutions were incubators for extremist ideology after several former members of the country's security service apparently joined the extremist Islamic State group.

Brian Dooley, director of the Washington-based group Human Rights First, said Rajab's detention appeared timed to come ahead of a planned United Nations meeting on human rights. He said other activists were prevented from leaving Bahrain to attend the conference in Geneva.

"Nabeel's arrest is a forceful, frightening message from the Bahraini government that it's moving against even activists with strong international connections," Dooley said in a statement.