Lewis Hamilton endured more testing misery after beaching his Mercedes in trackside gravel at the Bahrain International Circuit on Saturday.

The Formula One drivers' champion, who will be chasing a record eighth title this year, complained about sand in the desert on Friday.

He said the sandstorms being whipped up were unlike anything he had ever experienced at the track, but it did not appear to be a factor in Saturday's loss of control.

Hamilton was entering Turn 13, having completed 35 laps, when his rear end went and the car span off the track.

The Briton attempted to drive away but his car would not move, the tyres spinning and sinking, sending up a cloud of dust.

Hamilton got out and required a lift back to the Mercedes garage, with the session red-flagged while his car was pulled out of the gravel.

It was not the end of his session, however, with Hamilton soon back on the track. He completed 58 laps overall and was eighth quickest in the morning action, clocking a best time of one minute 33.399 seconds.

Daniel Ricciardo's McLaren led the way in 1:32.215 while former world champion Fernando Alonso completed 60 laps in the Alpine, with 1:32.339 good enough for second on the morning timesheet.