The New York Police Department is concerned about an Iranian-sponsored terrorist attack on the city, Commissioner Ray Kelly said Tuesday according to the New York Post.The concern is particularly poignant due to the city's large Jewish population, which stands at over 1.5 million - the largest Jewish population in any city worldwide outside Israel. Israel has had to cope with a number of terrorist attacks aimed at Jewish nationals living abroad. In the past year alone, terrorists have targeted Israelis in Thailand, India, Georgia, Kenya, Cyprus and Bulgaria. Prime Minister Binyamin Netanyahu has blamed Iran and its proxy Hezbollah for many of these attacks. Speaking at an anti-terror conference called NYPD SHIELD, Kelly said "We’ve been concerned about Iran for a while, and I think the history of those events throughout the world since January give us cause for concern."Kevin Yorke, a lieutenant in the NYPD's Intelligence Division, said that authorities feared that Iran would retaliate against an Israeli attack by lashing out at the US, particularly in New York. He also cited Hezbollah as a possible source of cross-border terrorism.“Within the last year, we’ve seen a worldwide increase in incidents involving the stockpiling of explosives, the surveillance of targets, and a number of very significant plots and attacks,” the Post quoted Yorke as saying. He added that the increase is in direct relation to Iran's nuclear-weapons program and tensions surrounding it.“Obviously if there’s any action involving Israel and Iran we have to be very cognizant of the potential of retaliation here in New York City,” he said.