The Syrian warplane screeched over the centre of town, forcing terrified civilians to run for cover as the deafening bomb explosion devastated families and shattered an otherwise peaceful Sunday.

Ambulances raced through Al-Bab, hurtling pell-mell through the clogged traffic, sirens wailing, to recover the casualties.

Overhead, the pilot circled before making another pass.

Rescue workers were already clawing through the rubble, desperately searching for the wounded when the pilot dropped his second bomb.

But even then, it wasn't over.

When he dropped the third bomb, this time not on a civilian home but on the nearby Islamic school, the huge blast kicked up a cloud of dust, stones and debris flying through the air, across the street and into nearby buildings.

It was a 20-minute sortie that medics said killed at least four people and wounded eight others -- the latest victims in a nearly 20-month uprising against Syrian President Bashar al-Assad that has morphed into civil war.

For the families, it means a lifetime of sorrow and a thirst for revenge.

For friends and neighbours who escaped unscathed, it was a reminder that death from the skies can happen to anyone and at any time.

Father of three and 42-year-old engineer Adnan Hamza left home on Sunday morning to chair a civil council meeting in the rebel-controlled town, 35 kilometres (22 miles) northeast of Syria's second city of Aleppo.

He never saw his wife and children again.

Mourners said he had been on his way to the meeting when he was mortally wounded in the doorway by the first air strike and then finished off by flying shrapnel in one of the other blasts.

The next time Hamza came home he was dead, his head wrapped in a bloodstained bandage and his body in a blanket, laid out on the floor of the front room where his brothers paid their last respects.

A friend said it would have been his last day as head of the council, because the position rotates among members every month.

Grown men fell on each other in tears. The talk turned quickly to revenge.

"I'll take revenge by my own hands. I was with him when the first bomb struck, he didn't die straight away. Then he was hit by shrapnel," cried his brother Safwan.

"I'll drink the blood of Bashar and I'll drink the blood of the pilot."

As news of Hamza's death filtered out, more and more mourners began to arrive. First his brothers, his friends and his cousins.

Then came the women -- elderly aunts and his young wife, and their three children, the youngest of whom is just three.

The elderly women, dressed head to toe in black abayas, fell on the body, prostrate and uncontrollable in their grief, beating their chests and imploring the heavens.

They brought with them young children, even babies to say goodbye.

"He was my friend for 30 years. He was a hero of the revolution," said Dr Mahmud Sayeh, an orthopaedic surgeon, standing in the corridor outside.

"He gave everything to the revolution. We will take over where he left off, all of us. And we will take revenge from Assad and his criminal team," he added.

Just another day of war and grief in Syria.