A bomb attack on an army bus in Damascus killed 14 people on Wednesday in the bloodiest such attack to strike the Syrian capital in four years, the SANA state news agency reported.
There was no immediate claim for the bombing but moments later shelling by government forces killed eight people in the Idlib region controlled by groups that have claimed such attack in the past.
"A terrorist bombing using two explosive devices targeted a passing bus" at a key bridge in the capital, the news agency said, reporting that 14 people had been killed and at least three wounded.
Images released by SANA showed first responders searching the charred carcass of the bus and what the news agency said was a bomb squad defusing a third device planted in the same area.
A military source quoted by the state agency said the bomb had been planted on the bus itself and was detonated as it passed near the Hafez al-Assad bridge, close to the national museum in the heart of the capital.
Later on Wednesday, the director of SITE Intelligence Group, which monitors militant groups online, said that a militant group called Qasiyun Brigades claimed responsibility for the attack.
Damascus had been largely spared such violence in recent years, especially since troops and allied militia retook the last significant rebel bastion near the capital in 2018.
The attack is the deadliest in the capital since a bombing claimed by the Islamic State jihadist group targeted the Justice Palace in March 2017, killing at least 30 people.
Around an hour after the Damascus attack, Syrian regime shelling struck the war-ravaged town of Ariha, in the northwestern region of Idlib.
The Syrian Observatory for Human Rights said the rockets struck a busy area at the time children were heading to school.
Three children were among those killed, the Britain-based war monitoring group said.
An AFP reporter saw at least five dead bodies as first responders treated the wounded and scenes of chaos filled the streets of Ariha.
"At 8am (0500 GMT) we woke up to the bombardment. The children were terrified and were screaming," said Bilal Trissi, a father of two who lives nearby.
"We didn't know what to do or where to go and we didn't see anything because of all the dust around us," he told AFP.
"They bombed us in our neighbourhood and in the market. There are children who died and people who lost their limbs... We don't know why, what are we guilty of?"
The Damascus bombing will challenge the government's assertion that the decade-old war is over and stability guaranteed for reconstruction efforts and investment projects to begin in earnest.
The government of President Bashar al-Assad has been striving to claw itself out of international isolation and had been making inroads in recent months.
The conflict that erupted with the brutal repression of unarmed protests demanding regime change in 2011 has left around half a million people dead, according to the Syrian Observatory for Human Rights.
Conflict on standby
It also led to the largest conflict-induced displacement since World War II, with half of Syria's pre-war population of 22 million forced to flee their homes at one point.
Assad's position once held by a thread, with his forces and their allies controlling barely a fifth of Syrian territory, but Russia's military intervention in 2015 marked the start of a long and bloody fightback.
Also backed by Iran and its proxy militias, government forces have recaptured nearly all key cities in the country, with US-backed Kurdish forces still running the northeast.
The Islamic State group's once-sprawling caliphate, that straddled swathes of Iraq and Syria, inexorably shrank to its death, which came in eastern Syria in early 2019.
Since then, the Syrian government's main focus has been the northwestern region of Idlib, where many of the rebels forced to surrender in other parts of the country have gathered.
The area is dominated by the jihadist group Hayat Tahrir al-Sham (HTS), which includes leaders of Al-Qaeda's former Syria franchise and over which Turkey has some sway.
HTS has not claimed attacks in Damascus in years however.
The remnants of IS group in eastern Syria have gone underground but continue to harass government and allied forces, mostly in desert areas, in hit-and-run attacks.
A truce deal brokered by Turkey and Russia, the two main foreign players in the Syria conflict, has effectively put fighting in Idlib on standby.
Sporadic flareups have kept the egion on edge, however, and Wednesday's shelling of Ariha was one of the most serious violations of the truce deal.
Assad insists he remains committed to reconquering all the territory lost to rebels at the beginning of the war, including the Idlib region.
(FRANCE 24 with AFP and REUTERS)