Mercedes pair Nico Rosberg and Lewis Hamilton dominated the track in the first and second practice sessions at the Malaysian Grand Prix on Friday.
Rosberg topped the timesheet in the opening session of the day as he edged ahead of his teammate by nearly half a second.
As a result, the practice was delayed, but the problem persisted for Magnussen as while in the pits, fuel leaked and reignited the fire.
In the second session, Hamilton rose to the top of the timesheet as his best lap was 0.223 seconds quicker than Rosberg, while Vettel and Raikkonen were third and fourth respectively.
Rosberg currently leads the driver rankings by eight points.