Facebook was inaccessible through phone and internet service provider Metfone for a number of hours yesterday morning, causing rampant speculation on social media that the government had engineered a blackout.

Users reported they were unable to connect to Facebook at about 9am, with service restored for most a few hours later.

Nhong Dinthan, vice managing director at Metfone, declined to comment yesterday, saying that he “did not know” anything about the service disruption.

When asked for the contact details of other senior company officials, he hung up.

A call centre worker at the company, speaking yesterday morning, said Metfone was “updating” its system, but did not explain why only Facebook was inaccessible to users.

When the Post called later, another customer service representative said there had been an “error” in the update but access had been restored by noon.

Although many netizens voiced their discontent with Metfone’s service yesterday, citing past problems, others questioned the timing of the service interruption.

“Sam Rainsy can now get a big protest, and I think the government is afraid that this information will spread out into the rural areas through Facebook, so Metfone blocked [it],” said Eng Vannath, support officer at the Open Institute, an NGO that focuses on technology and democracy.

Political blogger Ou Ritthy compared the incident to the flouted 31-day ban on foreign radio broadcasts before the election that was quickly retracted by the government after public outcry.

“In my opinion, this is a psychological test from the authorities to test the public reaction of Facebook users with respect to a [temporary blackout],” he said.

Minister of Post and Telecommunications So Khun and ministry director-general Mao Chakrya could not be reached for comment yesterday.

Council of Ministers spokesman Phay Siphan said the government had no policy to restrict social media and, in fact, encouraged information sharing.

“We do not have anything to do with [internet] service [provision].... That is between the company and the phone customer. On the government side, we have [a] policy of electronic freedom,” he said.

Ou Virak, president at the Cambodian Center for Human Rights, said he was reluctant to accuse the government of blocking Facebook, but called the incident “irregular”.

“I won’t say it’s blocking, but it’s certainly irregular. Particularly given that you could actually use the internet and go on any website but Facebook. It’s an interruption during a sensitive time,” he said.

Metfone is operated by Vietnamese telecoms operator Viettel, a wholly owned subsidiary of the Vietnamese military.

According to government statistics, Metfone claims a market share of 49 per cent of phone users and 46 per cent of the internet market.

In 2011, Metfone was one of a number of ISPs that blocked access to popular opposition news blogs Ki-Media and Khmerization.

At the time, anonymous employees at two other ISPs said their companies had been ordered to block sites on the government’s orders.