Long Island Rail Road trains on three branches experienced delays Friday averaging 10 to 15 minutes in both directions for part of the morning rush hour because of an oversize truck striking a bridge near Westbury, the railroad said.

The delays affected the Port Jefferson, Ronkonkoma and Oyster Bay branches, the LIRR said in an alert at 8:30 a.m., with trains operating at a reduced speed because of the vehicle strike.

Just before 9 a.m., the LIRR said one Montauk line train was also delayed 13 minutes by the bridge strike.

An oversize truck struck the bridge at Post Avenue about 8 a.m. and inspectors declared it structurally safe at 8:36 a.m., railroad spokesman Aaron Donovan said.

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There were no injuries reported, he said.

The trains were running on or close to schedule, the railroad said in a tweet at about 9:30 a.m.