The United Arab Emirates arrested political activist Ahmed Mansoor on charges of spreading sectarianism and hatred on social media, state news agency WAM reported on Tuesday, in a move criticized by rights groups.

Mansoor, an electrical engineer and poet, had used social media "to publish false information and rumors as well as promoting (a) sectarian and hate-incited agenda," WAM quoted the public prosecutor on Tuesday as saying.

His posts "harm national unity and social harmony and damage the country's reputation", the statement said, adding that Mansoor had been arrested on Sunday.

A trade and tourism hub, the UAE is an absolute monarchy which tolerates little public criticism of its ruling system and has prosecuted Mansoor and other pro-democracy activists for what it called insulting the country's leaders.

Mansoor was among five activists convicted of those charges in 2011 amid the "Arab Spring" protests calling for reform in other Arab states.

Amnesty International decried his arrest, and the rights group's regional director of research Lynn Maalouf called Mansoor "a courageous and prominent human rights defender".

"We believe Ahmed Mansoor was detained for the peaceful expression of his conscientiously held beliefs," Maalouf added in a statement.