Screenshot photo of Hamza bin Laden.

Crack American spooks were chasing Osama bin Laden’s ­fugitive son Hamza last night as al-Qaeda’s most feared wing vowed action worse than 9/11.

A secretive section of the US forces called The Activity is hunting the boy, 20 – dubbed the Crown Prince of Terror – in ­Pakistan’s tribal badlands.

Bin Laden’s three wives told US intelligence Hamza disappeared in the mayhem of the US Seals raid, which left his dad dead.

The boy was their husband’s closest ­confidante.

News of the manhunt came as ­influential Nasser al-Wuhayshi vowed “al-Qaeda In The Arabian Peninsular” would wreak a ­“whirlwind” revenge.

In a chilling warning to the West, he said: “You have to fight one generation after the other. The fight between us and you was not led by Osama alone.

“What is coming is greater and worse, and what you face will be more intense and harmful.”

The threat was made in a eulogy to bin Laden on the Islamist ­militant website As-Ansar.

AQAP is one of al-Qaeda’s most aggressive wings, staging several foiled strikes on US and Saudi targets, using unusual tactics like the two air freight packages containing bombs sent in October 2010. They were found on planes in Britain and Dubai.

But bin Laden’s death has given US intelligence a boost by freeing up hundreds of agents.

A source said: “Their only job was to look for bin Laden. Now they are being re-tasked. The hunt is on for his son.”

Meanwhile, CIA bosses are showing select members of the US Congress graphic photos of Osama bin Laden’s corpse.

The lawmakers are banned from taking copies away, the agency revealed yesterday. — Mirror