Syrian regime or Russian warplanes bombed aid trucks near Aleppo after a fragile week-long ceasefire ended as it appeared the bloody five-year war was fully back on late on Monday.

The UK-based Syrian Observatory for Human Rights said at least 32 people were killed in dozens of air strikes launched in and around Aleppo after the truce officially came to an end at 1600 GMT.

The war monitor said the aid trucks made a routine delivery to an area west of Aleppo city and were hit near the town of Urm al-Kubra, killing 12 people.

An official with the Syrian Red Crescent confirmed aid vehicles operated by the group had been targeted by air strikes as warplanes resumed bombings in Aleppo province.

Staffan de Mistura, United Nations Special Envoy for Syria, denounced the air raid. "Our outrage at this attack is enormous... The convoy was the outcome of a long process of permission and preparations to assist isolated civilians," he said.

Syria regime’s military on Monday declared that the seven-day, US-Russian brokered ceasefire was over.

An AFP news agency correspondent in Aleppo reported the northern city was being pummeled.

Sirens wailed as ambulances zipped through the eastern opposition-held half of the divided city, the correspondent said, describing the bombardment as "non-stop".

The US said it's prepared to extend the fractured truce, and Russia - after blaming opposition forces for the violations - suggested it could still be salvaged.

In the wake of the Syrian military declaration, US Secretary of State John Kerry expressed annoyance at Damascus and Moscow's handling of the ceasefire.

From the start, the truce had been beset by difficulties and mutual accusations of violations.

Aid deliveries to the besieged eastern districts of Aleppo have not reached their destination. The UN accused the regime of obstructing the delivery, while Russian officials said opposition forces opened fire at the delivery roads.

At least 22 civilians were killed in regime bombings over the last week, according to the Syrian Observatory, which uses a network of sources on the ground to compile its reports.

PHOTO CAPTION

Damaged buildings are seen in the Waer district in the central Syrian city of Homs, Syria September 19, 2016. REUTERS

Al-Jazeera