<span style="color: #222222;">In Iran, the government today denied a cover-up after it took days for the armed forces to admit a Ukrainian airliner was shot down by mistake last week.<br />''</span><br />''Iranian Government Spokesman said, some officials were even accused of lying and a cover-up meanwhile, but that was not the case. The comments came after a second night of demonstrations in Tehran against the authorities over the air disaster.<br />''<br />''President Hassan Rouhani promised a investigation into the air disaster in a telephone call with Sweden's Prime Minister Stefan Lofven.<br />''<br />''<span style="color: #222222;">The Ukraine International Airlines Boeing 737 was shot down shortly after it took off from Tehran before dawn on Wednesday last week, killing all 176 passengers and crew on board.</span><br />