"Units from the army are reestablishing security in the province of Latakia after killing a large number of terrorists and destroying their weapons," the television said, referring to rebels who had been in control of the town for more than two months.
Kasab, an Armenian town, is strategically important because it is located near the only border crossing with Turkey in sensitive Latakia province, the heartland of the Alawite sect from which Assad hails.
Rebel fighters including members of Syrian Al-Qaeda affiliate Al-Nusra Front withdrew from the town yesterday, the Syrian Observatory for Human Rights said, leaving only a small number of men behind.
On Sunday, the Britain-based Observatory said that government troops had entered Kasab, held by the rebels since March 21, but that fighting was still raging in the town.
More From This Section
"Fighting is still pitching soldiers against the rebels who stared there," Observatory director Rami Abdel Rahman told AFP.
Most rebels withdrew, he said, after "the army, backed by fighters from Lebanon's Shiite Hezbollah, was able to take the hills surrounding Kasab".
Rebels were short on supplies, and experienced Hezbollah fighters and Syrian special forces were able to advance, Abdel Rahman said.
Under frequent bombardment by government forces, Kasab was vital for rebels who used it as a staging post to transport their wounded to Turkey, which backs the opposition.
The Syrian government had accused Ankara of helping rebel groups seize Kasab.