U.S. and Yemeni officials say a group of American embassy personnel came under attack when a bomb exploded near their vehicle outside a restaurant in Yemen's capital.
State Department spokesman P.J. Crowley said no one was injured in the blast, which took place Wednesday evening in a commercial district of Sana'a. He said an investigation is ongoing.
Another U.S. official said the explosion disabled the vehicle, and that the embassy believes it was "likely" an attempt to target U.S. interests.
Yemeni officials said police arrested several suspects, including a Jordanian in his 20s.
They say the attacker threw a hand grenade at a car carrying a number of Americans as it was parked outside a restaurant frequented by foreign nationals.
It is unclear whether the attack is linked to al-Qaida militants in the country.
Al-Qaida last carried out an attack on a foreign embassy in October, when a rocket attack on a British embassy vehicle in Sana'a wounded several people. The rocket exploded near a car carrying Britain's number two diplomat in Yemen, wounding three bystanders and one staffer who was riding inside.
Last April, a suicide bomber in Sana'a blew himself up near a convoy carrying the British ambassador to Yemen, Timothy Torlot. The ambassador was unharmed, but three bystanders were wounded.
Al-Qaida in the Arabian Peninsula claimed responsibility for that attack.