This is reported by Censor.NET's correspondent.
The protest was organized by Svoboda All-Ukrainian Union, UKROP party, and 5.10 party.
Apart from Yatseniuk resignation demands, the protesters hold placards addressing U.S. Vice President Joe Biden, who is giving a speech in the parliament at the moment, with demands to protect freedom and democracy in Ukraine and help fight the corruption.
They read "Mr. Biden, ask our president about his friends godfathers," "Mr. Biden! Ask our President about political repressions."
The building and the Mariinskyi park nearby are being protected by law enforcers.