Formula One's pre-season testing was halted by a loose drain cover at Bahrain's Sakhir circuit for a second consecutive day on Friday.
The track action resumed after repairs at Turn 11 with the usual lunch break dropped and the session scheduled to run until 7 p.m. local time (1600 GMT).
Testing was stopped on Thursday when Mercedes' Lewis Hamilton and Ferrari's Charles Leclerc ran over the loose cover, and the floor of the latter's car had to be changed.
On Friday, Red Bull's Sergio Perez dislodged a different drain cover at the same turn with 27 minutes on the clock, again bringing out the red flags and further track repairs after an inspection.
Ferrari's Carlos Sainz had been fastest before the latest suspension, with the Spaniard also topping the timesheets on Thursday.
Drivers have only a day and a half of pre-season testing each, with three days allocated in total for teams to test with one car each. Some have said three days is insufficient for getting to grips with the highly sophisticated new cars.
The first race of the season is at the same Bahrain circuit on Saturday next week.
— Additional input from Reuters