DAMASCUS, May 5 (Xinhua) -- The jihadi groups have breached the recently declared truce in Syria's northern province of Aleppo with intensified shelling and a wide-scale offensive on Thursday.

The rebels in eastern Aleppo violated the truce just eight minutes after it went into effect at 1:00 a.m. Thursday (2300GMT Wednesday) with two mortars slamming west of Aleppo.

Later in the day, state news agency SANA said the rebels breached the truce with 20 mortar shells hitting government-controlled districts, killing at least three civilians.

The al-Qaida-linked Nusra Front and like-minded groups later unleashed a wide-scale offensive against a government-controlled town south of Aleppo, a military source told Xinhua.

The Nusra offensive started with assorted weaponry and artillery against the town of Khan Tuman in the southern countryside of Aleppo, the source told Xinhua on condition of anonymity.

The Syrian army responded to the attack, destroying a number of tanks, he said, adding that the attack was preceded with heavy artillery shelling followed by the rebels' attempt to advance toward the town from the area of al-Khalidiyeh.

Clashes erupted and various weapons were used, including the heavy ones, he added.

The Nusra Front has announced on its Twitter account the commencement of the battle to "liberate" the town and nearby areas with the help of the rebel groups such as Failaq al-Rahman, Ahrar al-Sham, and Nour Addien al-Zunki.

Meanwhile, the source said the Syrian army fired a rocket at an explosive-laden armored vehicle, which was approaching Khan Tuman, adding that another SUV outfitted with heavy machine gun was also destroyed along with its occupants.

It also said that Syrian warplanes carried out several raids on the approaching rebels and their reinforcements near the town.

The military source told Xinhua that the Syrian army succeeded in repelling the attack.

But later in the evening, the rebels renewed their heavy shelling on government-controlled areas west of Aleppo, according to pan-Arab al-Mayadeen TV.

Meanwhile, the Foreign Ministry in Syria has condemned the rebels' breach of the U.S.-Russian-backed truce in Aleppo, saying the "armed terrorist groups breached a truce in Aleppo that culminated tough efforts to which the Syrian Arab Army has fully committed since Thursday morning as agreed."

The ministry said that a few hours after the truce took effect, "the armed terrorist groups shelled the safe residential neighborhoods in Aleppo city," adding that "the crime of violating the truce in Aleppo reveals the real face of the terrorist armed groups."

"These terrorist groups which are backed by Turkey, Saudi Arabia, Qatar and other countries have no other aim but to kill Syrians and destroy their country, yet some insist on calling them 'moderate opposition'," the ministry said.

The ministry stressed that the terrorist attacks will not prevent Syria from fighting terrorism and working towards a political solution to the crisis through Syrian-Syrian dialogue which will lead to the elimination of terrorism and restoring security and stability.

A day earlier, the Syrian army announced its commitment to observe a 48-hour truce, or a regime of silence, in Aleppo. It came as the city has witnessed intense violence over the past 10 days, during which more than 120 people were killed and hundreds of others wounded.

The truce in Aleppo came to bring a lull to the troubled city that has witnessed the most violent shelling from rebels on government-controlled areas. Opposition activists also accused government troops of conducting airstrikes on rebel-held areas in the eastern part of the city.

The "regime of silence" has previously been announced to include areas in the countryside of the capital Damascus and the northwestern province of Latakia.