US Navy ships are patrolling the Yemeni coast to try to recapture 23 convicts who broke out of jail on Friday, in case they try to flee by sea.
Jamal al-Badawi was imprisoned for the USS Cole bombing
The fugitives, at least 13 of whom are linked to al-Qaeda, include a man said to have masterminded the 2000 attack on the destroyer USS Cole.
Another was linked to an attack in 2002 on the French tanker Limburg.
The US ships are part of the Dutch-led multinational Combined Task Force 150, which routinely patrols the area.
According to a US Navy statement, the vessels are "supporting the efforts of the government of Yemen to recapture suspected terrorists who escaped from a Yemeni prison".
"Ships from CTF 150 are monitoring international waters along the coast of Yemen in an attempt to either block possible maritime escape routes or capture the suspected terrorists if they make this attempt," the statement said.
The US did not say which or how many ships were involved in the search, but the aircraft carrier USS Theodore Roosevelt is in the region.
The fugitives include Fawaz al-Rabihi, who was convicted for the attack on the Limburg and had been sentenced to death, and Jamal al-Badawi, who received 10 years for the attack on the USS Cole.
Al-Qaeda's deputy leader in Yemen, Abu Assem al-Ahdal, may also be with them.
The men broke out of a jail in the capital Sanaa on Friday, tunnelling 140m to a nearby mosque and escaping as people left after prayers.
Seventeen US sailors were killed when two suicide bombers blew themselves up on an inflatable raft moored next to USS Cole in the southern Yemeni port of Aden in October 2000.
In October 2002, the Limburg was attacked off Yemen's south-eastern coast. An explosion killed one Bulgarian crew member and wounded 12 others.