Motion targeting Syrian government and its backers adopted as bombardment of opposition strongholds in Aleppo continues.

US legislators have passed a bill that would sanction the government of Syria and its supporters, including Russia and Iran, for war crimes and crimes against humanity in the country.

The bill was passed by the House of Representatives on Tuesday, imposing new sanctions on Syria.

The legislators accused the Bashar al-Assad government of war crimes in a five-year conflict that has killed almost 500,000 people, led to Europe’s worst refugee crisis in modern times, and given room for the Islamic State of Iraq and the Levant (ISIL) group to perpetrate its brand of global terrorism.

“What we have now is a grim lesson in human suffering,” said Republican Ed Royce, who is also chairman of the foreign affairs committee, the bill’s lead sponsor.

“We can see the ethnic cleansing going on. Even the UN calls this ‘crimes of historic proportions’. Enough is enough.”

Anyone that provides aircraft to Syria’s commercial airlines does business with the transportation and telecommunications sectors controlled by the Syrian government, or supports the country’s energy industry. They also would be subject to sanctions under the legislation.

“We want to go after the things driving the war machine: money, airplanes, spare parts, oil,” said Eliot Engel, the top Democrat on the House foreign affairs committee.

“Something needs to jolt this crisis out of its bloody status quo. This bill would give the administration more tools to do so. If you’re acting as a lifeline to the Assad regime, you risk getting caught up in the net of our sanctions.”

The House vote took place one week after Republican Donald Trump was elected US president.

UN condemnation

Also on Tuesday, UN member states overwhelmingly condemned escalating attacks against civilians in Aleppo and called for a ceasefire to pave the way for a peace settlement.

A resolution drafted by Saudi Arabia, which is backing fighters opposed to the Syrian government, was adopted by a vote of 116 to 15, with 49 abstentions, in the General Assembly’s human rights committee.

Russia and Iran, Syria’s allies in the war, were among the 15 who voted against the measure, which is expected to go to the full assembly next month.

The UN rights committee has voted every year to condemn Syria over the human rights crisis since the war began in March 2011.

Backed by Russia, Syria launched a fresh assault on opposition strongholds on Tuesday as diplomatic efforts to end the war remained deadlocked.

Intense air strikes hit several areas in Aleppo for the first time in more than two weeks, signalling the start of a major government offensive in Syria’s northern city.

Large-scale operation

The heavy bombardment of eastern Aleppo came as Russian armed forces announced the launch of a large-scale operation against opposition targets in Syria.

The air strikes killed at least 10 people in Aleppo city, according to the US-based Syrian Observatory for Human Rights and other monitoring groups.

“In the last few hours at least nine neighbourhoods inside the city of Aleppo have come under intense bombardment,” said Al Jazeera’s Osama bin Javaid, reporting from Gaziantep, on the Turkish side of the Syria-Turkey border.

“Residents from inside Aleppo tell us that there is chaos and mayhem in the streets – where there are streets still remaining.”