A couple in northern Indiana County awoke yesterday morning and discovered their Barack Obama lawn sign had been spray painted with a red swastika.

"I was really disgusted. It's completely un-American," said Kamal Youssef, an artist and engineer from Egypt who became a U.S. citizen in 1958. "Everybody should have his own feelings and ideas and opinions," but he and his wife were stunned that someone defaced the sign.

Neither Mr. Youssef, 86, who is Muslim, nor his wife, Maria, 75, who is Jewish and Christian Orthodox and became naturalized after immigrating from Czechoslovakia, believes the attack was targeted at them personally. They raised three children at their home in Highland Park, but said neighbors around their summer home in the Amish farming community in Dayton have known them for three decades.

State police at the Indiana barracks took a report and the trooper on call yesterday said the incident was under investigation.

Mr. Youssef's daughter-in-law, Rebecca Slak, who made the report, said, however, the same trooper told her if there was no damage to any property, just the free campaign sign, it might not be classified as vandalism. The police would increase patrolling in the area, he said.

Allison Price, a regional spokeswoman for the Obama campaign, said campaign officials have been in touch with the Youssefs. A campaign aide said it appeared to be an isolated incident and Obama staffers did not know of similar attacks in Pennsylvania or nationally.

Ms. Youssef said she plans to pick up a new yard sign from an Obama campaign office in Westmoreland County. But she will keep the defaced sign posted in the yard as well "as a reminder to people."

"This seemed particularly hateful to us. We hope people will stop and think a little bit about this," she said.

Ms. Slak, who lives in Smicksburg, said this was an unusual opportunity for her and her husband to explain what a swastika was to their 3-year-old son, Ivan. He wanted to know why the police wanted to talk to his grandmother.