India placed several states on high alert on Thursday after al-Qaeda launched a new branch to "wage jihad" in South Asia, seeking to invigorate its waning Islamist extremist movement.
Al-Qaeda chief Ayman al-Zawahiri said the new operation would take the fight to Myanmar, Bangladesh and India, which has a large but traditionally moderate Muslim population.
"We are taking the matter very seriously. Such threats can't be ignored," an Indian intelligence source told AFP after Wednesday's video announcement.
"We have asked the states to be on alert (especially) Gujarat, Madhya Pradesh, Uttar Pradesh and Bihar."
Experts said the group, which has seen its global influence overtaken by the Islamic State jihadist group fighting in Iraq and Syria, would struggle to gain traction in India.
Al-Qaeda once attracted jihadists from around the world to training camps on the Afghan-Pakistan border.
But the core movement, led by Zawahiri since the death in May 2011 of Osama bin Laden, has been eclipsed first by its own offshoots in Africa and the Arabian Peninsula, and now by IS.
"This is just a publicity stunt, it shows their desperation because IS is now showing that they are the real threat in the world," said Ajit Kumar Singh, research fellow at the New Delhi-based Institute of Conflict Management.
In a video statement on Wednesday, Zawahiri singled out Assam, Gujarat and Kashmir -- Indian regions with large Muslim populations -- along with Bangladesh and Myanmar as territories the new organisation would target.
"This entity was not established today but is the fruit of a blessed effort of more than two years to gather the mujahedeen in the Indian sub-continent into a single entity," he said.
Kashmir, India's only Muslim-majority state, has a long history of violence between separatists and security forces.
But Kashmiri separatists said al-Qaeda had no role to play in their struggle against Indian rule of the disputed territory.
"They (Al-Qaeda) have no scope here. Kashmir is a local political dispute and al-Qaeda has nothing to do with it," Ayaz Akbar, spokesman for separatist leader Syed Ali Geelani told AFP.
While still regarded as a threat to the West, al-Qaeda's most destructive strike remains the September 11, 2001 attacks by hijacked airliners on New York and Washington.
It is active in Afghanistan and Pakistan, where its surviving leadership are thought to be hiding out, but has been significantly weakened there by a decade-long campaign of US drone strikes on its hideouts.
Zawahiri called on the "umma," or Muslim nation, to unite around "tawhid," or monotheism, "to wage jihad against its enemies, to liberate its land, to restore its sovereignty and to revive its caliphate."
He said the group would recognise the overarching leadership of the Afghan Taliban leader Mullah Muhammad Omar, and be led day-to-day by senior Pakistani militant Asim Umar.