As rival groups battle each other in Yemen's Aden, experts and officials warn that extremist groups will seize the opportunity to stage attacks.
An improvised explosive device planted on a road outside a Security Belt Forces camp in Abyan exploded Thursday, killing 2 soldiers and wounding another.
Analysts warn that instability and unrest in the Yemeni government's temporary capital will open the door for further extremist violence.
Lawmakers and religious officials and institutions have denounced the incident, saying Egypt will remain united in the face of terrorism.
The Iran-backed Houthis have been collecting funds for Lebanon's Hizbullah, even as more than 24 million Yemenis are in need of humanitarian aid.
The attack, which President Abdel Fattah al-Sisi described as a 'terrorist incident', killed 20 people and injured 47 others.
Yemen's president vows perpetrators will be brought to justice after deadly attacks carried out by al-Qaeda, ISIS and the Iran-backed Houthis.
Only trials where evidence and testimony are accessible to everyone can turn the page on ISIS, said UN investigator Karim Khan.
With its first sanctions to designate elected officials, the US shows it will be watching even those who represent Hizbullah in government.
The rise in drone warfare targeting Saudi Arabia follows the prevalence of ballistic missiles by the Iran-backed houthis.