The police surrounded activist Nabeel Rajab's house in the Bahraini village of Bani Jamra at dawn, his family said on Monday. Security forces moved in to arrest the activist, seizing electronic devices and several other items from the house.

Shiite advocate Rajab is a known critic of the Sunni-dominated regime in Bahrain. He led protests against the ruling al-Khalifa dynasty in 2011, prompting a three-year jail sentence he received in 2012. The authorities later reduced the term to two years.

Only months after leaving jail in 2014, Rajab was rearrested over tweets in which he claimed that many members of Bahraini security forces had joined the "Islamic State."

He was sentenced to six months for insulting state institutions, but received a royal pardon for "health reasons" in July last year, after spending three months in prison.

'Frightening' message

The reason for the Monday arrest was not immediately clear.

Washington-based group Human Rights First linked the raid with an upcoming UN meeting on human rights. The group's director, Brian Dooley, claims that other activists were also prevented from leaving Bahrain.

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

Another prominent activists, Zainab al-Khawaja, decided to leave Bahrain only last week, after she was released from prison on "humanitarian grounds."

"It pains me to leave, but I leave carrying our cause on my back, and my love for my country in my chest," Khawaja said on leaving for her second homeland of Denmark.

Bahrain has been burdened by low-level unrest as the Shiite majority is pushing for more rights from the Sunni-dominated regime. Rights groups say Bahrain has detained dozens of government opponents, often sentencing them to long prison terms.

dj/kl (AFP, AP)