At least 28 civilians were killed in Syrian government strikes targeting rebel-held areas near the capital Damascus, a monitoring group said yesterday.
The planes targeted Zamlka, Arbeen, Haza and Beit Sawa in the Eastern Ghouta region, the Britain-based Syrian Observatory for Human Rights said.
Ten children were among those killed. More than 70 others were injured, the watchdog added.
Some victims are still under rubble, which could lead to a higher death toll.
In retaliation, rebels fired late yesterday several shells on areas in and on the outskirts of Damascus, killing one person and wounding 13 others, a Syrian police source told DPA.
The shells landed on Bab Touma and Al Amin street as well as areas in the north-eastern sector of the capital, the source said.
The new air strikes raised the number of civilians killed in the Eastern Ghouta region since December to more than 286, including 72 children, the Observatory said.
It added that the rebel shelling on Damascus has also killed some 74 people since November.
Eastern Ghouta, hit by heavy shelling and regime air strikes for the past two months, has been under siege by Syrian President Bashar al-Assad’s forces for more than four years.
A total of 400,000 people in the region have been largely cut off from humanitarian aid since 2013.
Several attempts to establish a permanent ceasefire in Eastern Ghouta have since failed.
In recent months, the Russia-supported Syrian forces have regained ground from Western-backed opposition fighters and militants.
Meanwhile, a fresh chlorine gas attack has hit northern Syria, the Syrian civil defence organisation White Helmets said late Sunday.
“Eleven victims arrived to our medical point and were suffering from breathing problems — three of them were from civil defence rescue teams,” Najjar, a nurse at a hospital near Saraqeb, told DPA.
According to the nurse and other activists, the barrel containing chlorine gas only partially exploded near Saraqeb due to a malfunction.
Najjar said that the victims were suffering from breathing problems at first but all left the hospital yesterday.
Dr Ahmed al-Asad, from the same hospital, said the victims were between 15 and 40 years old.
Both al-Asad and Najjar declined to name the hospital for fear it would be targeted by government air strikes.
US Defence Secretary James Mattis said last week that Washington was investigating the possible use of sarin gas by the Syrian government.

Two Canadians freed by militants reach Turkey
Two Canadian citizens who were being held by a militant-dominated alliance in northwestern Syria were released yesterday to Turkish authorities, the pair said.
Jolly Bimbachi and Sean Moore were held for several weeks by Hayat Tahrir al-Sham (HTS), an alliance dominated by a former Al Qaeda affiliate. They had crossed into Syria in December 2017 from Lebanon, where Bimbachi was fighting a custody battle for her two sons, she said.
“Things were going a long way, so I decided to take an illegal route and bring my kids through Syria into Turkey, and hopefully the Canadian embassy in Turkey will help us out,” Bimbachi said.
“It didn’t work out quite as I planned but I came into Syria on December 31 with a friend of mine, Sean Moore,” she said at Syria’s Bab al-Hawa border crossing with Turkey.
“They’re going to take us into Turkey, and in Turkey we are going to meet someone from the Canadian embassy.”
She did not explain the whereabouts of her children.