Family members and rights groups are calling for the release of Eritrea’s former finance minister, Berhane Abrehe, who was arrested on Monday days after publishing a two-volume book critical of the government.

Four security agents detained Berhane, a 74-year-old veteran of Eritrea’s war for independence, while he was walking with his son in the capital, Asmara, according to Solomon Habtom, a nephew.

“It was abduction,” Solomon told VOA, speaking from the U.S. “People who saw it witnessed that it’s an unfortunate tragedy, but this is the true nature of the government. Isaias has security agents who do that, and this is a continuation of his practice,” he said, referring to President Isaias Afwerki, who has ruled the country since it broke away from Ethiopia in 1991.

Berhane hasn’t been charged with anything, nor has the government made any statements regarding his arrest.

The arrest drew condemnation from human rights organizations. “We ask the Eritrean government to release Berhane Abrehe unconditionally and immediately and also his wife, Almaz Habtemariam,” Fisseha Tekle, a Horn of Africa researcher at Amnesty International, told VOA.

Almaz was previously arrested for helping her son leave the country without a required exit visa and has been in prison for more than a year, according to a family member and Amnesty.

Book: President rules like 'tornado'

The two-part book, “Hagerey Eritrea,” or “My Country Eritrea,” includes sharp criticisms of the government and calls for reforms in the country. Berhane takes direct aim at Isaias, saying he rules the country like a “tornado,” “flip-flops” on issues and is perceived to suffer from “schizophrenia.”

The writings have caused a stir among the Eritrean diaspora. Passages have circulated online, and paperbacks have been shipped in the U.S. and Canada and distributed at launch events, including one in Washington.

In a recorded message posted to YouTube earlier this month, Berhane demanded a public showdown with the president. “I am calling on you to debate me in front of the people of Eritrea on national television,” he said, speaking in Tigrigna. “I hope you will accept my invitation for debate and respond. Our debating points will focus on past and future plans of political, economic, cultural and social issues of the country.”

Such provocations are virtually unheard of in the tightly controlled country, and Berhane’s arrest didn’t come as a surprise.

“Everybody was expecting [he] was going to be arrested because that was the trend in Eritrea,” Fisseha said, adding that the arrest “is horrible because it is an old man being held incommunicado, and no one knows where he is right now.”

Berhane studied economics and engineering in Illinois, but he returned to Eritrea to join the struggle for independence in 1975. He had been removed from his ministerial post in 2012. He now joins a long list of former government officials, sometimes known as the G15, who have been imprisoned in Eritrea since 2001.

“It is a very sad story for the family and also for the country,” Fisseha said. “Remember, September marks the 17th year since members of G15 have been arrested in Eritrea. No one has heard about them for the last 17 years. No one knows their final state, so he is going to join his compatriots there.”

The arrest has also left some wondering about the prospects of reform in Eritrea following a historic peace deal with Ethiopia and other regional rapprochements.

“It’s not only about Berhane. Berhane is a symbol,” Solomon said. “We are happy for the peace process between Eritrea and Ethiopia, but we also want to see the end of this kind of dictatorship in the country.”