PHILADELPHIA (AP) — Philadelphia police will step up patrols around worship sites as they look for the person who left a severed pig’s head outside a city mosque.

The police department meanwhile hopes to enhance security video that shows someone throwing the animal’s head out the passenger door of a red pickup truck, Commissioner Charles Ramsey said Tuesday. No arrests have been made in the Sunday night incident outside the Al Aqsa Islamic Society in west Philadelphia.

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The Quran, the holy book of Islam, prohibits Muslims from eating pork, and pigs have been used to taunt or offend Muslims. Last year, attackers in Greece left a pig’s head and painted anti-Muslim slogans outside an Islamic studies center in Athens. Similar incidents have also occurred in France.

In Philadelphia, a caretaker told police he found the head near the door of the mosque when he arrived for work Monday morning. A day later, Mayor Michael Nutter pledged a $2,000 reward for information leading to a conviction in any hate crime case.

Nutter, who leaves office next month, took the opportunity to respond to Donald Trump’s talk of banning Muslims from entering the U.S.

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The mayor suggested that his city banish the Republican presidential candidate.

“Trump is literally trying to radicalize Americans against Muslims, and that’s not what America is about,” Nutter said.

Nutter called Trump’s proposal “flat-out ignorant” and said, “If I had the power, the only banning that would be done is that I would ban him from Philadelphia. We don’t have any room for that kind of stupidity here.”

On Monday, Trump proposed stopping Muslims from coming to America “until we are able to determine and understand this problem and the dangerous threat it poses.” His suggested ban was quickly condemned by other presidential candidates from both parties. The mayor of St. Petersburg, Florida, tweeted earlier Tuesday that he also would ban Trump from his city.

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