( CNN ) -- Islamist fighters battling for control of Somalia have threatened to close Mogadishu 's only airport , warning all airlines to stop flights into the Somali capital by early Tuesday . African Union peacekeepers keep guard recently at the international airport in Mogadishu , Somalia 's capital . `` Any plane which uses or lands at the airport , we will consider it a military plane and we will not be held responsible for what happens to it , '' the Al-Shaabab militia said in a Web posting . The statement said the airport would be closed at 1 a.m. Tuesday ( 6 p.m . ET Wednesday ) . The statement was posted on www.kataaib.net , a Web site frequently used by Al-Shaabab . A graphic posted along with the statement shows a plane about to land at Mogadishu 's international airport . As the plane approaches , a man with a shoulder-fired missile appears and a red-circle target is placed over the plane . The Somali word for `` Warning ! '' flashes at the same time . Nairobi , Kenya-based Daallo Airlines , which operates flights four times a week into Mogadishu , is `` monitoring the situation , '' the company 's chief executive officer told CNN . `` We have n't received any warning directly , '' Howard Leedham said . He said he was made aware of Al-Shaabab 's warning through the local media , and would not say if any of the four weekly flights would be canceled or rescheduled as a result . `` All I can say is we 're monitoring the situation very closely , '' Leedham said . `` We have employees down there , and so we 're monitoring the situation . '' Maj. Barigye Ba-Hoku , a spokesman for African Union forces in Somalia -- many of whom are based at Mogadishu 's airport -- said he has not received an official warning from Al-Shaabab about the airport 's closure , but `` we take the warning seriously . '' `` We have taken precautionary measures , but that 's all we can do , '' Ba-Hoku told CNN . Al-Shaabab is an Islamic militia that has launched a bloody battle to seize control of Somalia and oust Ethiopian forces , which are helping Somali government forces try to rout the Islamic fighters . It is a splinter group of the Islamic Courts Union , which pushed out Somalia 's transitional government in 2006 . The ICU was deposed in December of that year following Ethiopia 's military intervention . In its statement , Al-Shaabab said it has been forced to shut down the airport because it is being used by a variety of `` infidel forces , '' including Ethiopia , Burundi , and Uganda . Burundi and Ugandan forces make up the bulk of the AU mission in Somalia . Al-Shaabab also said U.S. and Israeli security officials `` regularly '' land at the airport . `` So based on all these issues , we -- Al-Shaabab fighters -- are notifying all business people in Mogadishu , particularly to those of the airlines , that the airport is officially closed from the date on 16th September , '' it said . Journalist Mohamed Amiin Adow contributed to this report .
NEW : Airline CEO says situation being monitored , does n't comment on flights . Al-Shaabab militants threaten flights with statement , graphic on Web . African Union forces spokesman says he 's not received official warning . Comment: