In the audio message,
the Sinai-based militant group Ansar Beit al-Maqdis, or ABM, allegedly announces its allegiance to ISIS, which calls itself the Islamic State.
The roughly 10-minute clip blames tyrants and their "Jewish agents and their allies" for decades of Muslim suffering. The message also calls ISIS "the emergence of a new dawn."
If verified, this would be a new, dangerous chapter for the deadliest group in Egypt. Since 2012, ABM's attacks have grown more daring and sophisticated. The group has killed hundreds of Egyptian police officers and soldiers. The largest attack was last month in the Sinai Peninsula, killing at least 31 soldiers. Analysts put the group's numbers at from the hundreds to roughly a thousand.
While ABM's attacks, until now, have almost exclusively targeted the Egyptian government, there is growing fear that an association with ISIS could expand the threat to civilian and tourist sites.
Egyptian security forces have been aggressively battling ABM since the overthrow of President Mohamed Morsy in 2013.
Numerous checkpoints dot northern Sinai to prevent the movement of weapons and fighters. The threat to security forces operating in this area is so severe that at times, a shoot-on-sight curfew goes into effect between Arish, the largest city in northern Sinai, and the Rafah border crossing with Gaza, according to security officials. After October's attack, the government authorized a three-month curfew for the northern part of the peninsula.
Officials in Egypt blame Hamas in Gaza for aiding the militant group, an accusation Hamas denies. Recently, the government relocated more than a thousand families away from the border in a move to eliminate cover for any tunnels between Egypt and Gaza and to create a buffer zone. AMB initially gained a foothold by exploiting the long-entrenched mistrust between local Bedouins and Egyptian authorities.
The state of fear created by ABM eventually started to alienate many of northern Sinai's residents. ABM lost support after assassinating Bedouin leaders who disagreed with their practices and beheading men accused of being informants.
ISIS or al Qaeda
Before ISIS' rise to power, ABM was often associated with al Qaeda. Similar messages on social media proclaimed the group's allegiance to al Qaeda leader Ayman al-Zawahiri, only later to be denied by the militant group.
In an article in Atlantic Council by Zack Gold
, he said there "appears to be an internal tussle in ABM over support for these international organizations." He also argued that if the militant group associates itself with ISIS or al Qaeda then it would lose its status as a "local hero" and become a "foreign agent."
Association with ISIS could also further damage ABM's image with most Egyptians. Egypt relies heavily on tourism and any organization that threatens this source of income risks loss of support.
U.S. State Department spokesperson Jen Psaki said the department will assess the issue.
CNN has not been able to independently verify the authenticity of the audio message.