Germanys flagship carrier Lufthansa said on Friday that its group airlines were canceling flights to and from Tehran until Jan. 20 inclusive due to the uncertain security situation of the airspace around the Iranian capital. Lufthansa said the move was a "precautionary measure" and it would decide if and when its flights to Iran would resume when it had more information. US officials said on Thursday that the government believed Iran accidentally shot down a Ukrainian airliner shortly after Iran fired missiles at two US military bases in Iraq, while Iran was on high alert. Iran has denied the allegations. All 176 people on board the jetliner were killed. A US official, citing satellite data, said Washington had concluded with a high degree of certainty that anti-aircraft missiles brought down the plane in error. The official said the data showed the plane airborne for two minutes after departing Tehran when heat signatures of two surface-to-air missiles were detected. There was an explosion in the vicinity and heat data showed the plane on fire as it fell. US military satellites detect infrared emissions from heat. US President Donald Trump said he believed "somebody could have made a mistake".