In a warden message dated Monday to Americans living in Yemen, the Embassy said the terrorist threat was not temporary and would continue for the foreseeable future. It urged Americans to avoid large groups of Westerners, vary their travel routes and times to and from work and limit travel within the capital, San'a.
"We are now experiencing terrorist actions previously unseen in Yemen," read the warden message, which also reminded Americans that there is an "active" al-Qaida presence in Yemen and Western interests "may continue to be targeted."
The latest warning comes more than a month after a suicide bomber killed seven Spanish tourists and two Yemenis near a temple linked to the ancient Queen of Sheba in the northern part of the country. An eighth Spaniard died about a week later at a Yemen hospital from injuries she received from the blast.
Yemeni authorities have said the suicide bombing's mastermind was Ahmed Bassiouni Dewidar, an Egyptian national and alleged al-Qaida operative who was killed in July while resisting arrest.
Al-Qaida continues to have an active presence in Yemen, the ancestral home of Osama bin Laden, despite government efforts to fight the terror network. Al-Qaida was blamed for the 2000 bombing of the USS Cole in Aden that killed 17 American sailors and the attack on a French oil tanker that killed one person two years later.