SLOVYANSK, Ukraine — Armored personnel carriers flying Russian flags drove into a Ukrainian city controlled by pro-Russia demonstrators today. Some of the troops aboard said they were Ukrainian soldiers who had switched allegiance.

An Associated Press reporter saw the six vehicles with troops enter the city of Slovyansk. Insurgents in Slovyansk have seized the local police headquarters and administration building, demanding broader autonomy for their eastern Ukraine region and closer ties with Russia.

PERTH, Australia — A robotic submarine resumed its search today for lost Flight 370.The Bluefin 21 sub surfaced early for the second time in as many missions, this time after experiencing technical difficulties. It was sent back into the water after its data was downloaded.As the search continued, more than 100 relatives of Chinese passengers on the plane walked out of a teleconference meeting with senior Malaysian officials, an act of defiance over a lack of contact with that country’s government and for taking so long to respond to their demands.