Updated

Authorities announced a $10,000 reward Friday for information leading to the arrest and indictment of a father accused of shooting his teen daughters and leaving them to die in a taxi.

An ongoing manhunt is under way for Yaser Abdel Said, 50, of Lewisville, Texas, wanted for shooting Sarah Yaser Said, 17, and Amina Yaser Said, 18, in his taxi Tuesday night. Police say they don't have a motive for the shootings, but believe a domestic issue may have led to the deaths.

A public viewing for Sarah and Amina Said was planned for 6 to 9 p.m. CST Friday in Dallas. Their funeral will be at 11 a.m. CST Saturday, also in Dallas.

Friends and Lewisville High School classmates of the Said girls posted photos and comments in a tribute to the sisters set up on the social networking site Facebook.com called "Rest in Peace, Sarah & Amina."

Click here to see photos.

The page's creator, friend Jenny Lee, encouraged people to document their memories of Amina and Sarah Said.

"We love you so much, and miss you already," she wrote.

Information about memorial services and developments in the case are also included on the Facebook page dedicated to the teens.

"How could anyone do this to two beautiful, bright young ladies?" wondered one visitor to the site.

A local Austin imam condemned the murders on the tribute page, and in another note, a girl identifying herself as a former classmate of Sarah's wrote that Yaser Said abruptly moved his family to Lewisville a few years ago because he was unhappy about a boy his older daughter, Amina, was dating.

Loved ones gathered Thursday night for a vigil to remember the sisters. The girls' mother, who has been in hiding since the shootings, attended.

The victims' brother made a statement at the vigil that the deaths have nothing to do with religion.

David Tull, a spokesman for the Irving Police Department, told FOX News that there's not a specific motive but police are aware of domestic issues within the family.

Tull wouldn't comment directly on shootings being tied to reports about the girls wearing Western clothes and disobeying their father's wishes.

Click here to watch a video report by MyFOXdfw.com.

Brigitte Gabriel, author of "Because They Hate: A Survivor of Islamic Terror Warns America," said the shootings point to an "honor killing."

"This crime has honor killing written all over it," Gabriel said. "The father was insulted and ashamed of how his daughters were behaving."

The daughters were bringing shame to Islam and the father took it upon himself to respond, Gabriel said.

"The father probably was seeing that this is going to bring shame on the family and he needed to eliminate that shame," Gabriel said.

One of the teens called 911 on a cell phone about 7:30 p.m. Tuesday and said she was shot, but she couldn't tell police where she was, police said.

Officers were dispatched to the area, which turned out to be about half a mile from the taxi, but didn't find anyone, according to reports. Police found the taxi with the bodies inside an hour later after a witness called and reported a suspicious vehicle in a hotel parking lot, police said.

Yaser Abdel Said is about 6-foot-2, weighing about 180 pounds with black hair and brown eyes. He was last seen wearing a black turtleneck shirt or sweater, a brown coat and tan pants. He is believed to be armed with a handgun, police said.