What is the fine-grained topic of the following text: A detachment of six Danish F-16s touched down at Sigonella air base in Sicily on 19 March, two days after the UN security council had passed resolution 1973 approving the introduction of measures against the Libyan state, including the imposition of a no-fly zone. Only return the topic.
Danish F-16s arrival in Sicily for Libyan no-fly zone enforcement