An unknown telephone caller making bomb threats to a Dillons grocery store kept more than 100 people hostage, demanding they disrobe and that the store wire money to his bank account.

Police safely led the 46 employees and 64 customers, some of whom had taken off their clothes, out of that store Tuesday after about 90 minutes. Threatening calls were also made to a second Dillons store that same day in Hutchinson, which was evacuated without incident.

On Wednesday, that second store and one other Dillons store in Hutchinson also received bomb threats, said police Lt. Steven Nelson. Police did not yet know if Wednesday's incidents were connected or were copycat crimes. Officers were investigating at both stores.

No one was injured and no money paid, police said.

In Newport, R.I., on Tuesday a bomb threat caused the evacuation of a Wal-Mart and led employees to wire $10,000 to the caller. FBI spokesman Rich Kolko said the incident appeared related to a plot in recent days targeting banks and stores near Phoenix, Detroit, Salt Lake City and Philadelphia.

Kolko said Wednesday that the bureau was looking into whether the calls were being placed from overseas and was compiling reports from local police departments to look for similarities between the cases.

The caller to the Hutchinson store where more than 100 people were held for 90 minutes appeared to have visual access to the store. Law enforcement officials were investigating whether the caller was out of state and may have hacked into the store's security system.

"If they can access the Internet, they can get to anything," said Hutchinson Police Chief Dick Heitschmidt. "Anyone in the whole world could have access, if that's what really happened."

The caller spoke to the store manager and demanded the female hostages take off their clothes and after 20 minutes made a similar demand of the males. The manager told the hostages of the caller's demands, police said.

Jim Peterson, one of the hostages, said some complied out of fear.

"A lot of women were really embarrassed being exposed," said Walter Merian, another hostage. "It already was scary enough without adding the embarrassment."

The manager pleaded with the caller not to harm anyone in the store, Peterson said.

"He was just beside himself," Peterson said. "Everyone was really scared. We didn't know if there was a bomb."

No bomb was found.

Dillons spokesman Sheila Lowrie said the company brought counselors to the scene.

"We're sorry the employees and the customers had to go through this," Lowrie said.