Two people were arrested after climbing to the top of the Empire State Building’s spire in New York City on Wednesday, where they staged an apparent marriage proposal and unfurled a large banner before being taken into police custody.

The pair were identified as Angela Nikolau and Ivan Beerkus, Russian urban climbers, or “rooftoppers,” who have gained international attention for scaling skyscrapers and landmarks in cities including Los Angeles and Tianjin, China.

Dressed in black clothing with their faces covered, the couple climbed well above the public observation areas of the iconic skyscraper, reaching the uppermost section of the 1,454-foot (443-metre) building. During the stunt, they displayed a large black banner bearing the message: “When the power of love beats the love of power, the world knows peace.”

Authorities have not disclosed how the pair gained access to the restricted section of the building. The New York Police Department said an investigation is ongoing.

According to CBS News, the two individuals are expected to face multiple charges, including burglary, criminal trespass, and reckless endangerment.

The Empire State Building, one of New York City’s most recognizable landmarks, maintains strict security measures, with access to upper maintenance areas restricted to authorized personnel.