World leaders and aid groups are calling for an end to the Syrian government’s bombing of opposition-held eastern suburbs of Damascus that has left hundreds of people dead in recent days.

The air strikes on rebel towns in the suburb known as eastern Ghouta were reported by several local opposition activist groups and a Britain-based war monitor.

The Syrian Civil Defence that works in opposition-held areas said its paramedics rushed to several areas after the shelling.

Syrian government forces have been pounding the area for days, hitting residential buildings, hospitals and infrastructure and overwhelming medics and rescue workers.

The bombardment has forced many among the nearly 400,000 residents to sleep in basements and makeshift shelters, and has overwhelmed rescue workers who have spent days digging out survivors from the wreckage of bombed buildings.

UN Secretary-General Antonio Guterres called for an immediate suspension of “all war activities” in the area where he said people are living “in hell on earth”. The UN Security Council is expected to vote on a resolution, called for by Sweden and Kuwait, ordering a 30-day ceasefire throughout Syria to enable delivery of humanitarian aid and evacuation of the critically sick and wounded.

Russia’s UN Ambassador Vassily Nebenzia called a 30-day ceasefire unrealistic, but Moscow said it would consider supporting the UN-proposed ceasefire if it does not cover extremists such as the Islamic State group and al Qaida-linked groups.

The Russian military is again supporting Syrian President Bashar Assad’s forces as it did in the all-out assault on the rebel-held half of Syria’s largest city, Aleppo, in late 2016, which drove the rebels from their enclave there.

German Chancellor Angela Merkel called for the European Union to step up pressure on Russia and Iran to end the violence in Syria.

“The regime is not fighting against terrorists, but against its own people, killing children, destroying hospitals, and this is a massacre to be condemned,” she told Parliament.

Besides Assad, Mrs Merkel said “Iran and Russia have a particular responsibility” as they are both supporting the government forces. She said Germany’s foreign minister plans to talk directly with his Russian counterpart and called for other EU nations to also do what they can.

“We need to do everything in our power to put an end to this massacre,” she said.

Russian news reports, meanwhile, said Moscow has increased its forces in Syria with several warplanes, including its latest fighter jets.

News outlets carried pictures of a pair of Su-57 fighters heading to land at Hemeimeem air base in Syria’s coastal province of Latakia that serves as the main hub for Russian operations in Syria. An early warning A-50 plane, four Su-35 fighters and four Su-25 ground attack jets also arrived at the base on Wednesday.