Syrian authorities have threatened to crack down on "armed groups" it says killed 120 members of its security forces in the northwestern town of Jisr al-Shughur.
On Tuesday, an activist in the town told the AP news agency that residents of the were preparing to face the Syrian security forces' operation.
Speaking to Al Jazeera, Reem Haddad, Syria's information ministry spokesperson, said "this afternoon 40 security officers were killed, and 80 have died since Friday".
The international media is banned from covering the uprising in Syria, making it nearly impossible to verify the state-controlled media's claims.
In a televised statement on Monday, Mohammed Ibrahim al-Shaar, the Syrian interior minister, said: "The state will act firmly, with force and in line with the law.
"It will not stay arms folded in the face of armed attacks on the security of the homeland."
The minister's threat of retribution came after Syrian state television said that the security forces who came under attack were on their way to the town in response to calls for help from residents, and that they died in an ambush.
"The armed groups are using weapons and grenades ... the people in Jisr al-Shughur are urging the army to intervene speedily," state TV said.
An activist in Jisr al-Shughur, who spoke to Al Jazeera on condition of anonymity, said that the situation in the city was "quiet" on Monday after the previous day's violence.
"[On Monday] we didn't have any particular events, the situation was calm. But we had some news that there was a group of armed forces headed towards us," he said.
"The Syrian television is always against the street. If we have hundreds of demonstrators, the Syrian TV will say dozens. There is a big gap between the media in Syria and what is happening in the street."
Syrian security forces have been conducting military operations in Jisr al-Shughur for several days as part of a crackdown on anti-government protests.
"The area there has been witnessing many clashes for the past few days," Al Jazeera's Rula Amin reported from Beirut in Lebanon.
"It is very difficult to verify the two different versions of these events.
"The official version of what is happening is that there are armed groups roaming the area ... that army and the security forces are facing hundreds of armed gangs, and this is a large number. Obviously the protests and confrontation between the protesters and the security police has taken a new turn."
"From the activists and the protesters, we know they have been keen on emphasising the protests are peaceful."
Our correspondent said over the past two days "we have seen on Facebook and Twitter debates even within those activists and opposition figures on the new phenomenon of some of the protesters resorting to arms, attacking the security forces, sometimes with weapons".
An activist told Reuters that police and members of the security forces in Jisr al-Shughur were killed by gunmen.
"Some people in some areas have taken up arms," he said. "The situation is grave, what is happening is an armed rebellion. I oppose violence from whatever side it comes from."
Fares Braizat, a Middle East analyst, told Al Jazeera there was a "war of pictures and a war of the media" going on in Syria.
"Now the only available version for viewers in Syria and outside Syria is the official version coming from Syrian TV or the Syrian official state agency," he said.
He said that following a massacre that took place in the Jisr al-Shughur area in the 1980s, "the people of this area have a longstanding revenge that they want to take out against the Syrian regime.
"So if violence escalates to unprecedented levels ... I think this is where the regime wants the process to be. I think the regime has for the past weeks been trying to turn this into a sectarian war."
France to seek UN vote
Rights groups say more than 1,100 civilians have been killed and at least 10,000 arrested in Syria since protests against president al-Assad's rule erupted in mid-March.
The Syrian government insists the unrest is the work of "armed terrorist gangs" backed by Islamists and foreign agitators.
Alain Juppe, the French foreign minister, on Monday said that his country was ready to approach the United Nations Security Council to vote on a draft resolution condemning the Syrian government for its violent crackdown on protests.
"I think the regime has for the past weeks been trying to turn this into a sectarian war."
Middle East analyst
"The situation is very clear. In Syria, the process of reform is dead and we think that Bashar has lost his legitimacy to rule the country," Juppe told a Washington think-tank after a day of talks with US officials including Hillary Clinton, the US secretary of state.
He said that there was a "risk" that Russia would use its veto to block the motion.
An earlier initiative to persuade the council to issue a statement criticising Syria collapsed in May when Russia, China and India opposed it.
Six human rights groups within Syria issued a joint statement on Monday condemning "the excessive use of force to disperse peaceful gatherings of unarmed Syrian citizens".
They also demanded an independent and transparent commission of inquiry "to unmask those responsible for the violence".
Source: Al Jazeera and agencies