12.18pm GMT

My colleague Paul Owen provides this summary of events so far today:



• Ukraine has accused Russia of carrying out an “armed invasion” after men in military uniform seized Simferopol airport in the largely pro-Russian Crimea region of the country. Reporters at the airport have pointed out similarities with the new Russian army uniform. The airport seems to be running normally.



• Russian forces have also blocked Sevastopol military airport, also in Crimea, Ukraine’s new interim government has claimed. But Russia’s Black Sea fleet, which is based in Sevastapol, has denied it has taken action at Sevastopol. However, it said it had stepped up measures by its “anti-terror units” to protect areas where parts of the fleet are located. The airport seizures come the day after pro-Russian gunmen took over the Crimean parliament.

• Ukraine’s parliament is asking the UN security council to call a session to consider the country’s current problems. It has also urged Russia to stop moves which it says undermine Ukrainian territorial integrity.



• Ukraine’s acting president Oleksandr Turchynov has dismissed the chief of staff of the armed forces Yuri Illyin, who was only appointed to the post by the since ousted president Viktor Yanukovych last week.

• Ukraine’s prosecutor has said it will ask Russia to extradite former president Viktor Yanukovych, who is wanted for alleged “mass murder”, if it is confirmed he is in Russia. Yanukovych is to give a press conference from an undisclosed location in Russia at 1pm GMT.



• Switzerland, Austria and Lichenstien are all freezing assets of the former Ukrainian government. Only Switzerland named the individuals affected, who included among them ousted Yanukovych and his son Oleksander. Switzerland’s chief prosecutor has also opened a money laundering investigation into Yanukovych and and his son,



• The leader of Russia’s far-right party, Vladimir Zhirinovsky, is in Crimea and on his way to Sevastopol. The controversial Zhirinovsky, who is deputy speaker state Duma speaker said Russia could help south-east Ukraine by providing fuel.



• As fears grow over Ukraine separating, Russian MPs have said that they plan to submit a bill to parliament that would make it easier for new territories to join the Russian Federation.