CARACAS (Reuters) - Venezuelan intelligence agents detained before dawn on Friday an 85-year-old activist who is the sole survivor of a clandestine group that fought against a 1950s military dictatorship, according to his family and Twitter feed.

Lawyer Enrique Aristeguieta is an outspoken opposition campaigner who regularly compares the 1952-1958 dictatorship of Marcos Perez to the current “narco-tyranny” of socialist President Nicolas Maduro.

His family and political party Justice First said he was taken from his home in Caracas in the early hours.

“(Intelligence agents) are in my house looking for me,” Aristeguieta tweeted just before 4 a.m., without giving further details.

Maria Alejandra Aristeguieta, his daughter, said in a statement they had no idea of his whereabouts.

“We demand the immediate liberation of Enrique Aristeguieta,” she wrote.

Venezuelan authorities did not respond to a request for comment.

Local rights group Penal Forum said Aristeguieta was one of 14 activists rounded up over the past week, among about 200 in total who are being detained by the Maduro government.

Critics say the ruling Socialist Party persecutes dissenters, while officials insist they are acting legitimately against people plotting against the government with U.S. support.