Two Howard County teenagers have been arrested in what county police are calling a string of hate crimes over the past several weeks that targeted two Asian-owned businesses in Elkridge.

The teenagers are 15-year-old boys, one from Columbia, the other from Elkridge. Each was charged with several counts of arson, destruction of property and harassment of a person for ethnic reasons. Their names were not released because they are juveniles.

Police spokeswoman Sherry Llewellyn said she did not know the boys' races. A source familiar with the case said one is white and the other appears to be of mixed race. The source asked not to be identified because the case is open.

The initial target of the attacks was the Great Wall, a single-room takeout Chinese restaurant in a Route 1 strip mall.

Police said that fireworks went off just outside the Great Wall on July 3 and 4. Then on July 16 and 18, fires were set on the roof.

The second time, a note was left telling the owners to move their business or expect more fires.

The harassers kept their word: On Thursday, a blaze was lit in the restaurant's dumpster, police said. Also that day, a rock was thrown through the window of the Dollar Shop, in a strip mall across the street from the Great Wall and owned by a Korean woman.

Another fire was set on the restaurant's roof Friday, and another rock shattered a window of the Dollar Shop, police said.

"Once we had two unrelated victims, and the only similarity between the two was that the business owners at each location are Asian, then the investigation went from the fire unit to the hate crime" team, Llewellyn said.

Finally, the restaurant received two more phone calls "of a threatening nature" about a half-hour apart Saturday, she said. Great Wall employee Xiu Yan Chen, 25, said she had received at least one other threat when she picked up the phone to take orders at the restaurant. She recorded the words on a scrap of paper:

"Do you know what happen about your store?" she wrote of one conversation. "It will be happen again."

Chen said the fires began shortly after a man asked to use the restaurant bathroom just before the business's 10 p.m. closing time. She told him the restaurant had no bathrooms and now suspects the incident was connected to the fires.

Llewellyn could not be reached late yesterday to comment on a possible connection.

Police said patrol officers spotted two teenagers throwing rocks at houses Saturday. The officers identified the teenagers as the boys in a photo that the Great Wall's owner, who is Chinese, took after eggs were thrown at him soon after the restaurant opened May 1.

Police then determined that the teenagers' cell phone numbers matched those on the restaurant's caller ID during the threatening calls and arrested them, Llewellyn said.

Dollar Shop owner Eun Il Oh said the damage to her store cost about $1,000 to fix. Yesterday afternoon, a man stood on ladder inside the store installing security cameras that Oh said cost $3,000.

"I was very upset," she said. "I cannot sleep."

Her brother-in-law, Kevin Yi, said that Oh took over the store less than a month ago.

"She thought she was coming to a good neighborhood," he said. "She was surprised by the vandalism and the boldness of it."

Howard County has increasingly become a destination for the Washington area's Asian community, drawn mainly by its high-performing school system.

Asians are the fastest-growing minority group in the county: According to an estimate by the Census Bureau, their population jumped by 23 percent, to 25,482, from 2000 to 2003.

Llewellyn said that none of the 12 previous hate crimes reported in the county this year targeted Asians. She said that 10 of those crimes were vandalism, mainly graffiti, and two were phone harassment.

Half of the crimes were directed at blacks, four targeted Jews and one was aimed at Muslims.

The final incident was an anti-God message spray-painted on a church, she said.