Police officials and sniffer dogs were found outside St. Mary’s hospital in London on Tuesday morning, heightening speculation that Kate Middleton, the Duchess of Cambridge, may be in labor. Middleton is almost a week late for her delivery, which was expected to take place Thursday.

People who had gathered outside the hospital premises saw heavy deployment of police officers, and said that some of them were also going inside the hospital's Lindo Wing through the side door early Tuesday, the Mirror reported. Middleton will give birth at the Lindo Wing, the same location where she had her first child, Prince George, on July 22, 2013.

A photographer close to Middleton’s personal assistant Natasha Archer had also reached outside the hospital shortly after security was beefed up, according to the Mirror.

"A couple of protection officers were seen in Paddington early this morning,” Niraj Tanna, a photographer camped outside the hospital, told the Mirror, adding: "Either it was a test run or she's in."

The sex of the royal baby has not been disclosed yet, but fans waiting outside the hospital reportedly received coffee and food from the Duchess and Duke in boxes with a pink ribbon. The ribbon's color has sparked another speculation that the royal baby may be a girl, despite the family saying it is not aware of the baby's gender.

A report from Express News said there was a possibility that the baby may be born on Wednesday, which would mark the four-year anniversary of the royal couple.

“The doctors don’t normally wait for more than a week,” a source from Lindo Wing told the Express News, adding: “They will probably already have been in touch with Kate and talked about which day will suit her best to go in and be induced if the baby doesn’t arrive in the next couple of days.”

Fans waiting outside the Lindo Wing to catch a glimpse of the royal baby took to social media to express their excitement.