New York City Mayor Bill de Blasio was booed Monday as he delivered the ceremonial first pitch at Citi Field.

Wearing a Mets jersey, the liberal mayor was at the ballpark to mark Opening Day between the New York Mets and Washington Nationals.

In a video posted online by the New York Daily News, fans can be heard greeting de Blasio with loud boos:

Fans also turned to Twitter to report the not-so-flattering welcoming:

[blackbirdpie url="https://twitter.com/Brokelyn/statuses/450681193936457728"]

[blackbirdpie url="https://twitter.com/tim_bays/statuses/450681430289682432"]

[blackbirdpie url="https://twitter.com/cho_jason0/status/450681307811823617"]

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