A Yemeni US embassy worker has been shot dead by masked gunmen in Sanaa. Sources have told Arabstoday that Qassim Aqlan - a high profile Yemeni official who worked in the investigation department in the US embassy - was shot dead by two gunmen on a motorcycle, whilst his car was passing through Assitteen street at west Sanaa. The sources added that Aqlan, who has been working in the embassy for more than 20 years, was assigned of following up coordination between the US embassy and the Yemeni government. The attackers, whose affiliation was not immediately clear, fled the scene straight away. Several security and intelligence officials in Yemen were assassinated in September in similar incidents. It is believed these assassinations are carried out by Al-Qaeda fighters in retaliation a military offensive held by the Yemeni army in Mat, which ended with driving Al-Qaeda out of all the footholds they seized in south Yemen during the turmoil witnessed in the country in 2011. The Yemen-based Al-Qaeda in the Arabian Peninsula and other militant groups strengthened their grip on parts of the country during an uprising that ousted veteran President Ali Abdullah Saleh in February. Washington, wary of the growing power of Al-Qaeda, has stepped up drone strikes on suspected militant positions, with the backing of Saleh's successor, President Abd-Rabbu Mansour Hadi.