An interfaith activist defending the rights of Christians in Dharmasraya regency, West Sumatra, to hold Christmas Mass was arrested on Tuesday for allegedly spreading hate speech on Facebook.

Sudarto of the human rights group Pusaka was reported to the police by Harry Permana, the chairman of a youth group in Kampung Baru hamlet, Sikabau village, Dharmasraya regency.

The hamlet is home to 16 Christian families who were reportedly prohibited from holding Christmas Mass.

Harry decided to report Sudarto after being told that the latter had posted about the ban on social media. The activist was arrested at his residence on Jl. Veteran, said West Sumatra Police spokesman Sr. Comr. Stefanus Satake Bayu Setianto as quoted by Antara news agency.

Stefanus said the police had interviewed witnesses and experts and examined screen captures of Surdarto's Facebook account, concluding that the activist had deliberately spread information that foments enmity against certain individuals or groups based on their ethnic, racial and religious backgrounds. He is also accused of spreading a hoax.

Sudarto has been charged with hate speech as stipulated under Article 45 and Article 28 of the Electronic Information and Transactions (ITE) Law and with spreading lies as stipulated under the 1946 Criminal Code.

The police have confiscated his phone and laptop as evidence.

The Jakarta Post previously reported that the Christian families in Kampung Baru were prohibited from celebrating Christmas in public but were allowed to do so in the privacy of their own homes.

They were reportedly prohibited from inviting visitors for a Christmas celebration or gather with other Christians for a Christmas Mass. The local administration finally allowed them to hold Christmas Mass only after their plight made national headlines.

Pusaka has been leading a media campaign to highlight the issue, with Sudarto himself openly criticizing the discriminatory policy on his Facebook account.

He wrote in one of his posts: "This morning I took my wife to her office. There was a report about the prohibition of Christmas Mass [...] in Kampung Baru hamlet in Sikabau village, Dharmasraya regency, West Sumatra.

"I have notified the head of the local office of the religious affairs ministry, but there was no response. I have forwarded [the issue] to the Office of the Presidential Staff [KSP]; I hope it receives good response."

He also posted: “I am not a coward, but if I have to fight intolerant groups and report the village [leaders] of Nagari Sikabau who prohibited Christmas prayers, I have the guts to do that. However, the victims will remain pressured and it [would] cost them their mental health."

The local administration denied claims that it had prohibited Christians from conducting religious services in private, but admitted that it had banned them from holding Christmas Mass.

According to Dharmasraya administration spokesman Budi Waluyo, the administration never officially prohibited the public from conducting prayers according to their respective beliefs.

“The Dharmasraya administration respects the agreement between village leaders in Sikabau and Christian residents who transmigrated from Kampung Baru. Both parties agreed that conducting religious services in their respective houses was not prohibited,” Budi said in a written statement received by the Post in December.

When asked about Sudarto's arrest, the regency's secretary, Adlisman, said: “[We] don’t need to provide further comments regarding the issue. Law enforcement officials are doing their duties, the regional government has nothing to do with it.

"The most important thing we can do is to create a comfortable atmosphere in the region.”

Human rights group Setara has condemned Sudarto's arrest.

“This is a strategy used by intolerant groups to silence critics. Unfortunately, the police and local government chose to placate these groups. Sudarto’s acts were part of his freedom of expression and it should be open for further discussion,” said Setara's Bonar Tigor Naipospos.