Washington, Mar 1 (IANS): The US is offering a $1 million reward for information on the whereabouts of Hamza bin Laden, the son of slain Al Qaeda chief Osama bin Laden, who is emerging as a leader in the terror group's network, the State Department has announced.

The reward was announced by Sales and State Department Assistant Secretary of State for Diplomatic Security Michael T. Evanoff on Thursday.

"He has released audio and video messages on the Internet, calling on his followers to launch attacks against the US and its Western allies, and he has threatened attacks against the US in revenge for the May 2011 killing of his father by US military forces," CNN quoted the Department as saying on Thursday.

It said that when Osama bin Laden was killed by US Navy Seals in Abbottabad, Pakistan, in 2011, items seized from his hiding place indicated that he was grooming Hamza bin Laden to replace him as the leader of Al Qaeda.

Hamza bin Laden is married to the daughter of Mohammed Atta, the lead hijacker in the September 2001 attacks on the World Trade Centre, the State Department said.

As American officials hunt him down, UN member states are required to freeze Hamza bin Laden's assets and comply with a travel ban and arms embargo, according to the State Department bureau of counter-terrorism.

US officials estimate Hamza bin Laden is aged between 30 and 33 years.