PHILADELPHIA — An Ohio man arrested Sunday for allegedly plotting a Fourth of July terror attack in Cleveland also planned to detonate a truck full of explosives on Labor Day in Philadelphia, according to court filings.

Demetrius N. Pitts, 48, of Maple Heights, Ohio, described Philadelphia as his hometown and the city he knew best, according to an affidavit filed Monday charging him with attempting to provide material support to terrorists.

In meetings last week with an undercover FBI agent posing as an al-Qaida operative, Pitts allegedly laid out a list of Philadelphia landmarks that he considered high-value targets for an attack, including City Hall and the William J. Green Federal Building at 6th and Arch streets, a location he dubbed the “goody spot” for an attack because it would “hit ‘em in the gut.”

Federal authorities declined to discuss Monday how far along they believed Pitts was in planning his purported terror strikes or whether they believed he had the capability of pulling off attacks in Philadelphia or in Cleveland.

FBI agents arrested him Sunday, just days before a July 4 attack he was planning on a downtown Cleveland park — the site of the city’s annual fireworks display.