Intense clashes broke out Thursday in a rebel-held area east of the capital Damascus, as the Syrian army continues to battle armed militant groups elsewhere, local media and activists said.
Sounds of explosions were heard on Thursday echoing from the Damascus' eastern suburb of Jobar, a rebel-held area and a stage for ongoing clashes between government troops and rebels there.
Huge smoke bellowed over Jobar and could be seen from districts inside Damascus, in what activists said is the heaviest shelling by government troops against rebel-held areas in months.
Witnesses in the nearby Abbasiyeen neighborhood told Xinhua over the phone that they hadn't heard such powerful and rattling sounds of firing and explosions since the beginning of the crisis.
The state news agency SANA said the Syrian troops were carrying out a series of intense operations in Jobar, destroying positions of "armed terrorist groups," killing many of them.
SANA said the operations started before noon Thursday and are ongoing in tandem with other operations against rebel positions in the nearby suburbs of Arbeen and Zamalka.
The military's heavy shelling against Jobar and nearby suburbs came after rebels bombed two buildings government troops were positioned at near the suburb, activists said.
The rebels unleashed a mortar attack against districts in the capital as part of their usual response to government offensives.
The mortars slammed into residential areas of Dwaila, Adawi, and Jaramana, local media said, without reporting details about casualties.
Jobar has posed a threat to the government-controlled eastern districts of the capital throughout the country's long-running conflict as rebels positioned in the suburb have repeatedly attempted to breach the capital from Jobar.
Syrian troops said they have discovered tunnels dug by the rebels that connected Jobar with other rebel-held areas in the eastern countryside of Damascus as well as areas near the Abbasiyeen district in Damascus.
The government also said that most of the mortar shells that struck residential areas in Damascus during the crisis were manufactured and fired from Jobar and Mlaiha, which was recently recaptured by the Syrian army.
Also Thursday, Syrian troops continued to clash with the radical rebel groups in the southern al-Qunaitera province, bordering the Israeli-occupied Golan Heights, a day after the al- Qaida-linked Nusra Front seized the al-Qunaitera crossing.
The pan-Arab al-Mayadeen TV said Syrian troops clashed with Nusra fighters at the crossing, adding that Syrian forces succeeded in seizing the countryside village of Jaba.
The report added that the Syrian air force struck positions of the so-called Islamic State (IS), previously known as the Islamic State in Iraq and the Levant (ISIL), around the international airport of the eastern province of Deir al-Zour, killing many of them.
In Aleppo, IS fighters bombed and destroyed a building used by the rival Nusra Front in the town of Awram in Aleppo, killing dozens of Nusra fighters.
The surge in the radical rebels' operations came just days after the United Nations Security Council adopted a resolution, promoting international actions targeting rebel groups and militants in the region, particularly the Nusra Front and the Islamic State.