New Delhi, July 1 -- A couple scaled the 1,454-foot antenna atop New York City's iconic Empire State Building on Wednesday, unfurled a peace banner and appeared to stage a proposal before descending, prompting a police response and an ongoing investigation.

The pair, dressed in dark clothing, were seen near the top of the Midtown Manhattan skyscraper holding a large banner that read: "When the power of love beats the love of power the world knows peace."

According to the New York Post, the woman appeared to be wearing a black cat mask as the two dangled from the antenna, at times hanging on with only one hand, drawing the attention of onlookers below.

After remaining near the top of the spire for about 30 minutes, the pair climbed down...