The Syrian government has blocked a premiere live stream website a day after one of its users broadcast images of a bombing believed to have been carried out by President Bashar al-Assad's forces.

Bambuser – a mobile live stream service based in Sweden – has been in close contact with activists on the ground in Syria for over eight months. The dissidents use the service to broadcast streaming video of conditions in their country in real time. With foreign media blocked, online citizen journalism has become a crucial medium for telling stories from within Syria's borders. Bambuser's executive chairman, Hans Eriksson, says approximately 90-95% of the live video coming out of Syria is streamed through Bambuser.

"The prime purpose of it is to get pictures out of the country, and show the world what's going on, both in terms of the violence but also of the determination of the citizens," Eriksson told the Guardian.

On Thursday, a number of those citizens informed Eriksson and his colleagues that Bambuser was no longer accessible. While the site has been blocked by the Assad regime before in a limited capacity, Eriksson says this time the government has attempted to eliminate access nationwide.

"From yesterday morning we heard that you couldn't access Bambuser.com and you couldn't use the Bambuser mobile application to stream live video," Eriksson said. Syrian activists have managed to work around the attempted blackout and videos are still emerging, Eriksson noted.

The blackout came after a Syrian citizen using Bambuser streamed video of the aftermath of a pipeline bombing in the besieged city of Homs. Archived footage from the scene shows a massive cloud of smoke billowing over the neighborhood of Baba Amr while gun shots and shelling can be heard in the background. Activists claimed the government was responsible for the bombing. The live stream was picked up by several international news organizations including al-Jazeera, CNN, the BBC and Sky News, who referred back to Bambuser.com.

"We can only assume that some people from the Syrian government were watching those pictures as well," Eriksson said. He believes the blackout was a concerted effort on the part of the regime to stifle any similar broadcasts. "We're just assuming that's the rationale behind it and we would be very much surprised if someone else had taken an action and blocked Bambuser."

It's not the first time an authoritarian regime has imposed a nationwide blackout on the site. Shortly before his ouster last year, Egypt's Hosni Mubarak blocked Bambuser. Bahrain, meanwhile, has been preventing access to the site for at least seven months.

According to Eriksson, "between 50 and 200" Syrian activists use Bambuser on a given day. He says the individuals Bambuser works with in Syria are highly organized and well aware of the potential risks they face. Last week a Syrian broadcaster filming from a rooftop was shot at. While he escaped unharmed, his partner was hit in the leg, Eriksson said.

"They're taking risks, but they know what risks they are taking," he said. "When it gets on every TV channel in the world, it means a lot to these guys down there being shot at, being arrested, being tortured, being killed."

Eriksson stresses that Bambuser is not in the live streaming business to make a profit, but are operating in the interest of free speech. "We've been watching live video now for 11 days in a row from Homs. Pretty much 10, 12 hours a day and it's basically constant gunfire and shelling," he said. "As a human being you understand that this is a situation that is not acceptable."