The 23-year-old Briton, F1's first black driver, was jeered and insulted when he moved between the McLaren motorhome and the team's garage at the Montmelo circuit Saturday.
Circuit director Ramon Pradera instructed staff to erect barriers around the team's paddock for Hamilton's safety, the reports said. Banners making references to Hamilton and team boss Ron Dennis were removed while the stands directly above McLaren's garage were cleared to ensure no debris could be thrown down when the car returned to the pit lane.
''We would like to make a plea to the fans to behave correctly,'' Pradera said. ''No type of offensive behaviour can be tolerated.''
Hamilton was widely blamed in Spain for Fernando Alonso's failure to clinch a third straight championship last season after the Spaniard joined from Renault.
Alonso, who has since rejoined Renault, finished third in the drivers' standings, with rookie Hamilton finishing second.
