SAKHIR, Bahrain - Bahrain's Sakhir circuit has filled troublesome drains with concrete and carried out additional welding work after loose covers halted last week's Formula One testing for Saturday's season-opener.

The governing FIA said in a note on Wednesday that remedial works had been carried out around turns seven and 11, with welding at certain areas around the track.

Triple world champion Max Verstappen said last week more checks were needed after testing was halted two days in a row amid fears the latest high-downforce cars were making such incidents more likely with their aerodynamic suction.