Farmville, N.C. — Three relatives, including a 16-year-old high school student, were shot and killed in an armed robbery at a Pitt County convenience store Sunday night.

Three armed men burst into the Hustle Mart in Farmville and shot the store owner's son, Mokbel Mohamed "Sam" Almujanhi, 16, as he mopped the floor, according to sheriff's investigators. They also shot the owner's nephew, Nabil Nasser Saeed Al'mogannahi, 26, and cousin, Gaber Alawi, 24.

Around 10 p.m., a customer couldn't find anyone to help her in the store at Stantonsburg Road and N.C. Highway 121, so she looked behind the counter and discovered the men lying on the floor, investigators said. One was pronounced dead at the scene, while the two others died at the hospital.

Farmville residents and pastors gathered to pray at the store Monday. They expressed shock at the shootings, especially the teen, who was a "very well-liked" 10th-grader at Farmville Central High School, according to school spokeswoman Heather Mayo. Classmates put a tribute to him on the store window.

Tony Muhssen, a cousin of the victims, spoke out on Tuesday about the shooting.

"A father lost his only son. Sam was only 16 years old...(he was) a great person," Muhssen said.

Kelvin Reid, one of Sam Almujahni's classmates, helped organize a candlelight vigil Monday evening for his friend. Hundreds of people showed up to mourn.

Pastor Mickey Fields shared Scriptures with mourners. During the week, he was the teen's school bus driver.

"My heart is saddened – I'm pretty sure, like everybody else – and distraught that something like this would happen," he said. "I pray that justice will be served for such a wonderful person."

"We don't understand how this could happen in our community," said Preston Hartley. "We are all scared. This has hurt the whole town."

All three victims were family members from Yemen, and they were hardworking, kind people, customers said. Al'mogannahi and Mokbel had moved from New York to help run the store after Al'mogannahi's brother suffered health problems.

"If you come in this store and you didn't have money, didn't have quite enough money, they would lend you the money," said customer Mattie Harper.

Pitt County Sheriff Neil Elks said investigators were getting a huge amount of tips after the reward money was increased to $10,000. Crime Stoppers has offered a reward of up to $5,000 for anonymous tips that help solve the crime. The victims' family added another $5,000 to that reward.

Police set up checkpoints throughout the neighborhood Monday evening to solicit information.

"(This was) very tragic, very disturbing (and) 100 percent unnecessary the way these guys were shot and killed," Elks said. "I have never seen anything quite as tragic and heinous as this crime has been."

Investigators say they have been interviewing potential witnesses, including Sam's classmates.

Cash was scattered throughout the store and in the parking lot, and there were no signs of a struggle, according to Christy Wallace, a sheriff's office spokeswoman.

The funeral is set for Tuesday afternoon at a mosque in Greenville.

Investigators asked people to look closely at the clothing of the man wearing a baseball hat in the surveillance photos.

Anyone who can identify the men in the surveillance photos or who has other information is asked to call Crime Stoppers at 252-758-7777 or text "PITTGV" and the tip to 274637.