PERTH, Australia (AP) — As a robotic submarine dived into the ocean to look for lost Flight 370, angry Chinese relatives stormed out of a teleconference meeting Wednesday to protest the Malaysian government for not addressing them in person.

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 were downloaded but there’s been no sign of the plane, according to the search coordinator.