BEIRUT -- Syrian government forces pressed their assault on the eastern, rebel-held neighbourhoods of Aleppo on Tuesday, opposition activists said, while state media reported that rebel shelling of the government-controlled part of the city left six dead at a university campus.
Activists meanwhile said the death toll from a suicide bombing at a Kurdish wedding in the northeastern city of Hasakah the previous night had risen to at least 34. The attack was claimed by the Islamic State group, which said its fighter had targeted a gathering of a Kurdish political party, without mentioning a wedding celebration.
Issam Amin, a local media activist, said a teenager detonated an explosive vest when he was stopped by men at the entrance of the wedding's reception. The Britain-based Syrian Observatory for Human Rights, which tracks the civil war through a network of activists on the ground, said 11 of the fatalities were children.
The attacks underscore the chaos of the Syrian conflict. The civil war has lately focused around Aleppo, where hundreds have been killed since the collapse of a U.S. and Russian-brokered ceasefire two weeks ago. There are several other fronts open between rebels and the government across the country, while Islamic State militants continue to stage large-scale attacks against all sides of the conflict.
Tuesday's shelling on Aleppo University's School of Sciences killed six civilians, some of them students, according to the Observatory and state media. State media said 47 were wounded.
Rebels said pro-government forces were attacking the city from the south in a bid to penetrate its opposition-controlled areas, where the UN estimates 275,000 people are trapped in a government siege. The Islamic Front rebel coalition said on Twitter that its factions repelled an advance on the Sheikh Saeed neighbourhood.
The Observatory said the government offensive is accompanied by airstrikes on the contested neighbourhoods. The monitoring group says 420 civilians have been killed in and around Aleppo since the collapse of the ceasefire, mainly in the rebel-held east of the embattled city.
Health facilities and hospitals have come under repeated attack in the offensive, prompting global outcry.
In Geneva, the UN human rights chief decried an unfolding "calamity" in Aleppo and condemned the Security Council for scuttling resolutions that would prohibit war crimes.
Zeid Raad al-Hussein said the Security Council should adopt rules to limit veto use by its five permanent members in cases of war crimes, crimes against humanity, or genocide. The U.S., France and Britain, as well as several UN officials, have said that Russia and the Syrian government's actions in the war could amount to war crimes.
International efforts to end the fighting suffered another serious blow on Monday, after the United States suspended direct contacts with Russia on halting the war in Syria, underscoring the deep mistrust between the two powers.
The move is likely to scuttle any chances of delivering desperately needed humanitarian aid to besieged communities and of breathing new life into moribund peace talks, though U.S. Secretary of State John Kerry insisted Tuesday that Washington has not abandoned peace efforts.
Kerry said the U.S. would still discuss Syria with Russia as part of multilateral negotiations, but not bilaterally.
"We are not giving up on the Syrian people. We are not abandoning the pursuit of peace," Kerry said in a speech focused on trans-Atlantic ties at an event hosted by the German Marshall Fund in Brussels.
"Together, the Syrian regime and Russia seemed to have rejected diplomacy," he said, arguing that they were opting for a victory at the expense of "the broken bodies, bombed-out hospitals and traumatized children of a long-suffering land."
UN Secretary-General Ban Ki-moon meanwhile called on the U.S. and Russia to resume talks on a Syria truce. Ban told reporters in Strasbourg, France, on Tuesday that he will hold talks soon with U.S. Secretary of State John Kerry and senior Russian officials in Brussels.
"I will strongly urge (them) to resume their negotiations so that there will be a cessation of hostilities," Ban said, adding that a ceasefire is vital to supply aid to besieged parts of Aleppo and provide the opportunity for political talks to recommence.
Also Tuesday, the Russian Foreign Ministry said its embassy compound in Damascus came under insurgent shelling the previous day.
One mortar shell landed near the residential compound and two more by the embassy building, the ministry said, adding that no one was harmed. It blamed the shelling on the al Qaeda-linked Fatah al-Sham Front, formerly known as the Nusra Front, and another insurgent group. It blamed the attack in part on U.S. policy in Syria, which it said "provokes further bloodshed."
Associated Press writers Jamey Keaten in Geneva, Lorne Cook in Brussels and Nataliya Vasilyeva in Moscow contributed to this report