SANA'A: Assailants fired a rocket at a convoy carrying Britain's No. 2 diplomat in Yemen and killed a Frenchman working for an Austrian oil company Wednesday in a pair of attacks that heightened fears over the safety of Westerners in a country facing a growing militant threat. There was no immediate claim of responsibility for the attack on the British convoy, but the violence casts doubt on the effectiveness of the Yemeni government's US-backed campaign to uproot Al-Qaeda militants, who have found a haven in parts of the mountainous, impoverished nation where the central government's control is weak. The diplomatic car was carrying five staff members, including the deputy chief of mission, to the embassy in Sana'a when it came under fire, apparently from a rocket-propelled grenade. One embassy official suffered minor injuries and was undergoing treatment, while the rest were unharmed, Britain's Foreign Office said in a statement. It was the second attack in less than six months to target British officials in the country, and the latest since Yemeni authorities recently boosted security around embassies in Sana'a after receiving information that Al-Qaeda was planning an attack. The embassy's deputy chief of mission, Fionna Gibb, was in the car, but not injured. Britain's Foreign Office said in a statement one staff member suffered minor injuries. In London, British Foreign Secretary William Hague condemned the “shameful attack” and said it “will only redouble Britain's determination to work with the government of Yemen to help address the challenges that country faces.” Three bystanders also were wounded, a Yemeni security official said. A Yemeni who arrived at the site soon after hearing the explosion said he saw two people fleeing the scene. “Next to the site we found a bag with parts of the weapon launcher,” Ali Mossad said. The attack came a day after a visit by third-ranking US diplomat William Burns to discuss the security situation. A Yemeni security guard also shot and killed a Frenchman contracted with the Austrian oil and gas company OMV in a separate attack outside the Yemeni capital, the company said in a statement. The Frenchman was working for OMV as a procurement officer. A British national was also wounded in the attack and was hospitalized. The motive for the attack was under investigation, but OMV said it “currently sees no political background for the action.” OMV is an oil exploration and production company and has been active in Yemen since 2003.