(CNN) -- A British citizen who worked for a Yemeni company has been killed by a car bomb in the volatile country, the British Foreign Office and a Yemeni senior security official said Wednesday.
The explosion went off in the Aden province town of Mualla when the man turned on his vehicle, and the blast could be heard more than a mile away, the security official said.
The official said a bomb was hidden under the vehicle and he believes that al Qaeda was behind the attack.
"The way the attack took place only proves that al Qaeda has been watching his moves days prior to the attack," the official said. Al Qaeda in the Arabian Peninsula has a strong presence in Yemen.
The Foreign Office says it is providing assistance to the victim's next of kin. However, authorities are not releasing the victim's name at the family's request.
Yemen has been wracked by anti-government protests and insurgent violence. The Foreign Office advised British citizens not to travel to Yemen, and urged all British nationals there to "maintain a heightened level of vigilance and keep a low profile at all times."
"We believe that terrorists continue to threaten further attacks including in Sanaa, Aden and other urban areas."
Journalist Hakim Almasmari and CNN's Antonia Mortensen contributed to this report