UPDATED at 11:10 A.M. on 2018-02-27

A Vietnamese activist blogger who was detained by security forces in Hanoi for 23 hours while they questioned her about a book she wrote was escorted home Sunday night and placed under house arrest, some of her fellow activists said.

Security officers apprehended Pham Doan Trang on Saturday to ask her about her activities and a book entitled Politics for Everyone that she published last year, the activists said, adding that the internet service and electricity in her house were cut off.

“This seems to be an ongoing effort to put more pressure on me before they arrest me,” Trang said, according to a Facebook post on Sunday by fellow activist blogger Trinh Kim Tien, who spoke with Trang on the phone.

Trang's 500-page book "is very useful for the Vietnamese in the sense that it makes politics easy to understand for ordinary audiences,” Tien wrote. “Its second edition soon will be available on Amazon. The police have been extremely concerned about where copies of the book are being printed.”

The Luat Khoa Tap Chi (Journal of Law) blog, which Trang co-founded, issued a statement on Sunday protesting her detainment after she was abducted from her home by security officers and was forced to go to the headquarters of the investigative security agency under the Ministry of Public Security.

The blog post condemned Trang’s abduction, saying that she was not informed by the security agency of any arrest or detention order.

It also said that the actions of the security officers constitute a crime of “abusing one's position or authority to unlawfully arrest, hold or detain a person” under Article 377 of the Penal Code or “unlawfully arresting or detaining someone” under Article 157.

Authorities also forced Trang to sign documents verifying interviews she has done since 2015, Tien said.

“Before letting her go, they did not forget to threaten her that if she makes this a big story, they would come after her with something bigger,” Tien wrote. “Trang is not allowed to go anywhere. They wanted her to stay quiet and cooperate with them.”

On Tuesday, Paris-based Reporters Without Borders (RSF) condemned the government's persecution of Trang and her family and called for international pressure on the regime.

The group also urged Vietnam to end its crackdown on independent journalists and bloggers and called on the European Parliament not to ratify a free trade agreement between the bloc and Vietnam that is scheduled for approval in the coming months and would take effect by the end of the year.

"The arrest of someone such as Pham Doan Trang, who has been praised internationally for the courage and quality of her published writing, represents a new level in the Vietnamese government's drive to suppress independent journalists and bloggers," said Daniel Bastard, head of RSF's Asia-Pacific desk, in a statement. "The international community should immediately draw the appropriate conclusions."

Another temporary detainment

This is not the first time Trang has been temporarily detained and questioned about her activities.

On Nov. 16, authorities detained and interrogated Trang and two other activist bloggers shortly after they met with representatives of the European Union to discuss the situation of human rights in Vietnam.

Police confiscated Trang's belongings, including her computer and phone, and escorted her home at midnight on the same day.

Copies of Trang’s book, which is considered politically sensitive in Vietnam, were seized by customs agents in the central coastal city of Danang on Feb. 9 when they were shipped into the country from abroad.

Trang recently received the Homo Homini Award from People In Need, an international human rights organization based in the Czech Republic that recognizes individuals dedicated to the development of human rights, democracy, and nonviolent solutions to political strife.

Reported by RFA’s Vietnamese Service. Translated by Emily Peyman. Written in English by Roseanne Gerin.