A spate of burglaries has hit downtown Portland businesses – including restaurants – in recent weeks, with thieves entering in the dead of night to rifle cash registers and, in at least one case, walk off with a safe.

Portland police confirmed at least six break-ins since July 28, and said the incidents shared similarities – method of entry, what was stolen – though they’re not yet sure that means they’re connected.

“It’s a terrible feeling to get a call at 6:45 (in the morning) and learn you’ve been broken into,” said Bryna Gootkind of LB Kitchen on Congress Street. “It’s a hard business already, and to learn you’ve been broken into and lost money is terrible.”

Gootkind, who co-owns two locations in Portland with chef Lee Farrington, said her breakfast-lunch restaurant in the East End was hit early Saturday morning.

There was no sign of a forced entry, and the register and safe were gone. That meant a loss of between $700 and $1,000, she said, or roughly half of a day’s gross take.

“It is hard to say why it’s occurring,” Lt. Robert Martin of the Portland Police Department said, dismissing the idea that full registers in a busy tourist season could be an explanation. “We can see something like this any time of the year.”

Martin said he didn’t know whether the incidents were linked. Though several bore similarities – restaurants broken into, their registers emptied – some were different, he said.

A list of burglaries Martin provided included several restaurants, a clothing store, and an optometrist: Maine Oyster Co., 38 Portland St.; Maine Juice Co. at 129 Spring St.; Wallace James Clothing at 112 High St.; Boda restaurant at 671 Congress St.; Little Tap House at 106 High St.; Leavitt & Parris at 200 Kennebec St.; and Eyes on Rosemont at 152 Middle St.

In some cases, there was property damage, and at Eyes on Rosemont nothing at all was taken.

Gootkind said the burglar entered her restaurant through an unlocked door. It’s unclear, she said, whether the door had been left open or the culprit got lucky guessing the keypad combination. Police recovered the restaurant’s register and safe together, but they asked Gootkind not to divulge where. Gootkind said the key to the safe had been stored in the register; when police recovered the safe, the key was locked inside and all the money was gone.

Tablets and laptops sitting around the restaurant were left undisturbed, a detail that puzzles Gootkind. She also wonders why the burglar didn’t just take the money from the safe in the restaurant, instead of carrying out both the safe and register.

“What else is odd is they left a roll of dimes in the register,” she said. “They took all the money except a roll of dimes.”

John Herrigel, owner of Maine Oyster Co., said the burglary at his restaurant took place sometime overnight between Saturday night, Aug. 3, and Sunday morning, Aug. 4. People who live in the building reported the break-in to police on Sunday morning, he said. The burglar had to climb into the backyard to reach the window that was the point of entry. About $500 to $700 was stolen, which was two to three times the amount of money usually left in the register overnight, Herrigel said. “It hurt a little more,” he said.

Like Gootkind, Herrigel was puzzled that the burglar ignored tablets, alcohol and other valuables lying around the restaurant.

Herrigel, who said he feels he’s been “so trusting” about security until now,  is taking steps to beef up security at his oyster bar. He’s installed more secure locks and is improving the backyard fencing. He’s also spoken with his staff about not leaving a lot of money in the register overnight.

Tim Nickerson, who owns Maine Juice Co., says his security camera caught a view of the man who burgled his Spring Street store on Aug. 5. The intruder jimmied open the back window, wrenched open the register with a crowbar, and then stole about $600.

The security footage begins with the noise of the break-in, followed about 90 seconds later by the first image of the burglar – a tall, thin white man with shoulder-length dark hair, wearing a light-colored shirt. He immediately began trying to pry open the register. As he worked, the occasional car or pedestrian passed by the front of the restaurant, oblivious to what was going on inside.

The burglar worked on the register for about six minutes. Then, curiously, he opened the fridge, took out a tub of almonds soaking in water and poured it over the register, Nickerson said. The nuts were for a batch of almond milk, but Nickerson doesn’t think the man was thirsty – more likely, it was to cover up any fingerprints.

“It’s pretty miserable being a local business owner and having this happen to you,” Nickerson said in an interview Saturday.

Now, Nickerson feels the need to invest in a full security system. “And that means more monthly fees,” he said.

Portland police said they are actively pursuing investigative leads. They have not made any arrests.