( CNN ) -- Gunmen on a motorbike killed a Russian military instructor and wounded a second Tuesday in Yemen 's capital of Sanaa , two senior police officials said . They used silencers and needed only seconds for the attack , eyewitnesses said . `` We only realized when the two Russians were on the floor and a motorcycle was seen escaping the scene , '' said Saleh al-Matari . `` They escaped by using side streets and driving through residential areas . '' Security forces arrived 10 minutes later , witnesses said . The wounded man was taken to a hospital , according to police . The two victims were advising Yemen 's army as private security contractors , said the police officials , who spoke on condition of anonymity . They were walking out of their hotel when they were shot . The Russian Embassy would not confirm that the victims were Russian . Last month , a German security expert was shot dead as he walked out of a Sanaa supermarket . Yemen is the most impoverished country in the Middle East and is plagued by two major bloody conflicts . Shiite Houthi rebels have fought a separatist battle for years but recently came to a cease-fire agreement with the government of the majority Sunni nation . Last week , one of their representatives in Yemen 's parliament was shot dead by gunmen on a motorcycle in Sanaa . Yemen is also a home to al Qaeda in the Arabian Peninsula , which many analysts believe is the most dangerous wing of the terrorist network . U.S. counterterrorism officials have said that AQAP strives to attack targets outside of Yemen . With the help of drone strikes allegedly carried out by the CIA , Yemen 's military put militants in the country 's tribal region on retreat last year , but AQAP regularly carries out terrorist attacks on soldiers and officials .
Witnesses said that they used silencers and needed only seconds for the attack . Two bloody conflicts plague the impoverished country . Shiite rebels have long fought for independence , and al Qaeda has a key hub in Yemen . TL;DR A U.S. drone strike killed at least 12 people on Sunday near Yemen's southern city of Aden, according to Yemeni officials.