Pakistanis across the U.S., regardless of whether they supported Benazir Bhutto, mourned her on Thursday and worried that her assassination could destabilize their homeland and threaten the safety of family members living there.

"I imagine this is how the people of this country felt after Kennedy's assassination," said Syed Hassan, a Houston resident who moved from Pakistan 20 years ago. "When these kind of things happen, it just shatters you."

At least half a million Pakistanis live in the United States, with the largest concentrations in New York and New Jersey, according to Boston University professor Adil Najam.

Mian Zahid Ghani, a former journalist with a Pakistani news agency now living in New Brunswick, N.J., predicted Bhutto's assassination would force cancellation of Pakistan's upcoming elections. He said many Pakistanis would blame President Pervez Musharraf for the killing, bringing "a lot of chaos and unrest."

"It has already started today. There might be a civil war. Musharraf should be planning his exit," Ghani said.

New York City is home to the nation's largest Pakistani community, with more than 100,000 residents who trace their heritage to that country, according to Mayor Michael Bloomberg, who released a statement Thursday deploring the assassination.

The city stepped up security outside the Pakistani consulate on the Upper East Side of Manhattan and the residences of the U.N. ambassador and the consulate general. Bloomberg said security also would be increased outside Pakistani airlines, Pakistani banks and in parts of the city with the most Pakistani residents.

In a neighborhood dubbed Curry Hill, just south of midtown on Manhattan's East Side, Pakistanis were glued to television sets as news of Bhutto's death unfolded.

"I love her. It's very sad," said Sharmen Talukbar, 32, who struggled not to weep as she bustled behind the counter of a Pakistani restaurant.

In another nearby restaurant, waiter Abid Asghar — who was wearing a Yankees cap — worried about the aftermath of the slaying.

"This is very bad for Pakistan's image abroad," said Asghar, who emigrated to the United States 12 years ago. "In Pakistan, it's sad to say, there is no tolerance."

In Chicago, Syed Raza was driving his taxi when he heard the news that the 54-year-old former prime minister had been gunned down in Rawalpindi.

He called his regular clients to say he was too grief-stricken to work and within an hour, stood on a corner in the heart of Chicago's main Pakistani neighborhood holding a small picture of Bhutto.

"She was the only hope for Pakistan," said Raza, who has worked as a cab driver for 20 years.

Like other Pakistani-Americans, Raza spent much of Thursday on the phone with friends and relatives in Pakistan. Raza's wife was in Karachi with the couple's three children and told him she could hear gunfire and see smoke from riots in the city.

"There's big chaos there," he said. "I'm very worried about my wife and kids."

In New Jersey, Hameed Butt, a former president and chairman of the Pakistani League of America, heard the news of Bhutto's death Thursday morning by phone from his brother, who lives about 100 miles from Lahore.

"I don't have words to say," said Butt, a retired chemist who has lived in Edison, N.J., since leaving Pakistan in 1971. "I'm so shocked ... She was a symbol of modern Islam."

In Southern California, Muneer Haq was reading stories online about Bhutto's assassination at the Islamic Society of Orange County mosque in Garden Grove.

Haq, who emigrated to the U.S. in 2005 but whose family remains abroad, said he was devastated by the news and concerned about his family's safety.

"When you see back home what's going on you ask 'Why is this thing happening in my country?'" said Haq, an accountant at the mosque.

Bhutto — who studied at Radcliffe College and then Harvard University — was warmly remembered by those who met her on her trips to the United States.

Jim Carr, executive vice president of Harding University in Searcy, Ark., recalled a visit she made to Arkansas in 1991 to give a lecture.

On the way to Searcy, Bhutto told Carr she wanted to get her hair done. His secretary helped arrange an appointment, and when she was through, Bhutto left a $10 tip for the $15 styling.

"She said, 'Jim, I paid $165 for the same thing yesterday in New York,'" Carr said.