For two days in a row this weekend, Target experienced a register outage that caused long lines at the national retail chain and forced some customers to pay with cash.

Target experienced an “internal technology issue” Saturday that lasted about two hours.

Joe Poulos, the company’s senior director of communications, said its technology team worked quickly to identify and fix the issue, which he said was not a data breach or related to security. “No guest information was compromised at any time,” he said. After the initial outage ended, Target posted an apology on social media stating that the registers were “fully back online.”

But then on Sunday, the company seemed to experience yet another outage at its registers.

At a Target store in Phoenix, Joshua Mcbride said fellow shoppers were “annoyed” at the situation and that there were about 50 people waiting in line to pay Sunday afternoon.

“The lines were wrapped around the place,” Mcbride said. “They were super long, and all the managers were saying the entire system had crashed, and that they were only able to accept cash because their credit card systems were down, as well as the Target system itself.”

In a statement Sunday, Poulos said Target uses a separate vendor to accept card payments, and that vendor experienced an issue at one of its data centers.

He said Target was unable to process certain card payments at some stores for about 90 minutes.

While it was not clear how many stores were affected, Poulos said the issue was resolved, and no payment information was compromised at any time.

He also said Sunday’s issue was unrelated to Saturday’s trouble.

“We never want to disappoint any guests, and we’re working tirelessly to ensure these issues don’t happen again,” he said.

Mcbride, who said he waited about 20 minutes to pay, said managers relayed that their computers needed to be rebooted and that they were on the phone with Target’s corporate office.

“The managers seemed kind of frantic, but they gave us $10 off all of our bills,” Mcbride said.

Register trouble also hit other big cities, and shoppers shared their frustrations online.

“More @Target problems,” tweeted one person in Minneapolis. “Can’t pay with credit or debit. Cash or check only.”

And a customer in Arkansas tweeted: “#Target fail again today. In Little Rock no one was letting customers know it was happening. Just letting you try a card & then telling you you’d need cash or a check, which I haven’t had in three years. Very chaotic & frustrating.”