Syrian state television reports that government troops and tanks are storming a volatile northwestern town in order to remove what it called "armed groups."
The move comes against the backdrop of a harsh government crackdown on national protests against President Bashir al-Assad that first began in March.
It also comes as international outcry increases over Syria's actions, which reportedly have included the use of helicopter gunships to fire on protesters.
Amid news of the latest government offensive, British Foreign Secretary William Hague has said the UN Security Council must make a "clear statement" on Syria by proceeding with a resolution condemning the crackdown.
European states have drafted a proposed UN resolution condemning the Syrian authorities' use of force in the crackdown and calling for its end.
A UN spokesman said Secretary-General Ban Ki-moon had been trying to contact Assad but was told the president was unavailable to speak.
International media have been denied access to the country, making developments difficult to track.
The town of Jisr al-Shughour has been the scene of intense violence in recent days. Authorities say armed gangs killed 120 troops in the town in the last week. Refugees and rights campaigners say the violence came from soldier-on-soldier violence after some troops refused to fire on unarmed civilians.
Rights campaigners say more than 1,000 people have so far been killed in the government crackdown.
Thousands of Syrians have fled Jisr al-Shughour, part of a stream of some 4,000 refugees that Turkish officials say have escaped to Turkey.
The United States earlier accused the Syrian government
of creating a "humanitarian crisis" and called on it to halt its offensive.
compiled from Reuters reports