Bombing of Military Bus in Syrian Capital Kills 14

President Bashar al-Assad has tightened his grip on Damascus, but the attack suggested that militants who oppose him can still do harm.

A brazen attack on a military bus driving through the Syrian capital, Damascus, killed 14 people on Wednesday, according to state news media, a reminder that President Bashar al-Assad’s grip on power remains tenuous even in a major government stronghold with no active rebel presence.

No organization immediately claimed responsibility for the attack, which the government called a “terrorist bombing.” While rebel groups operated in and near the capital earlier in the war, and jihadists linked to the Islamic State and Al Qaeda often staged deadly suicide bombings, they were mostly defeated and driven out years ago.

But the blast suggested that militants opposed to Mr. al-Assad still maintained some ability to operate in the capital.

A decade of war involving rebels, jihadists, Syrian government forces and their allies from Russia and Iran has killed more than half a million people, sent millions of refugees fleeing abroad and left many Syrian cities heavily damaged.

Mr. al-Assad has largely managed to defeat those who sought to remove him from power and is gradually restoring ties with his neighbors. But it is a Pyrrhic victory; the economy is destroyed, one-third of Syria’s territory remains outside of his control, and harsh economic sanctions by the United States and other countries have deterred investments that could help him rebuild.

According to the United Nations, 5.6 million Syrian refugees remain outside the country and few plan to return because the economy is so bad, their communities are destroyed or they fear arrest or persecution by Mr. al-Assad’s security forces if they go home.

In a report released on Wednesday, Human Rights Watch said many Syrian refugees who returned to their country were subjected to abuses and struggled to make ends meet.

Out of 65 interviews with Syrians who had returned home from Jordan or Lebanon, or with their relatives, Human Rights Watch found 21 cases of arbitrary detention, 13 of torture, 17 disappearances, three kidnappings and five extrajudicial killings, the report said.

The group concluded that it was not safe for refugees to return to Syria.

The bombing Wednesday morning struck a military bus that was carrying soldiers down a main thoroughfare on the east side of Damascus. SANA, the Syrian state news agency, said that three explosive charges had been stuck to the bus before it departed and that two of them detonated as it drove through the capital.

A video on the agency’s website showed the bus still smoldering beneath an underpass, with its doors and windows blown out.

In Syria’s northeast, the last pocket of the country controlled by rebels, shelling by government forces killed at least 13 people on Wednesday in the city of Ariha, according to residents and the Syrian Observatory for Human Rights, which tracks the conflict from Britain.

The dead included a number of children, rescue workers said.