Al-Qaeda leader Ayman al-Zawahiri appealed to Muslims on Wednesday to attack US, European, Israeli and Russian military targets in a speech on the 18th anniversary of the September 11 attacks.
He is believed to be hiding somewhere in the Afghanistan-Pakistan border region.
“If you want jihad to be focused solely on military targets, the American military has presence all over the world from the east to the west,” he said in a 33-minute, 28-second video produced by the group’s as-Sahab Media Foundation.
“Your countries are littered with American bases with all the infidels therein and the corruption they spread.”
The al-Qaeda hijackings on September 11, 2001 – its most notorious attack – killed nearly 3,000 people when commercial airliners slammed into the World Trade Center’s twin towers and the Pentagon while another crashed in rural Pennsylvania.
The SITE Intelligence Group, which tracks the online activity of armed groups, reported in the video al-Zawahiri, 68, called the 9/11 attacks unacceptable because civilians were harmed.
He also criticised “backtrackers” – referring to former fighters who changed their views in prison.
“Just as they conspire and join forces against us everywhere, we must chase them down everywhere at a time and place of our choosing. Be inventive and creative in your methods,” he added.
Over recent years, al-Qaeda has been engaged in fending off competition in from its chief rival, Islamic State of Iraq and the Levant (ISIL or ISIS).
ISIL rose to prominence by seizing large swaths of Iraq and Syria in 2014, declaring a “caliphate” and establishing affiliates in multiple countries across the Middle East and North Africa.
A UN report said the “immediate global threat posed by al-Qaeda remains unclear”, but it warned some would-be ISIL recruits could turn to the older organisation.
Al-Qaeda members, meanwhile, have taken a lower profile using regional conflicts in Afghanistan, Syria and Yemen to entrench themselves.
The Yemen branch has been the most active, exploiting the chaos of the civil war to carry out bombings, shootings, and assassinations in an effort to expand its footprint.