The president of the union that represents Philadelphia school police said the school district's reliance on nonunion, per-diem officers may have been a factor in allegations that officers failed to prevent attacks on Asian students at South Philadelphia High School last week.

Michael Lodise, president of the School Police Association of Philadelphia, said per-diem officers, who lack medical insurance and other benefits, sometimes think: "I'm not going to risk myself for $95 a day."

When at least 30 Asian students were attacked by African American students at the high school Dec. 3, Lodise said, six of the 10 officers on duty were per-diem employees. The district uses them to save money.

Evelyn Sample-Oates, a district spokeswoman, challenged Lodise's numbers. She said records showed that 11 officers and a sergeant were assigned to South Philadelphia High, and that only five of the 11 were per-diem workers.

"As far as we know," she said, "the per diems don't act differently" from full-time officers.

Permanent and per-diem police receive the same four weeks of instruction, including four hours of diversity training, Sample-Oates said. They do not carry guns and do not go through the city's Police Academy.

After the attack, the district boosted the school police assigned to South Philadelphia High to 15 officers and a sergeant. Eleven of the officers are permanent staff, she said.

The district's force comprises 421 permanent officers and 230 per-diem officers, Sample-Oates said.

Under the union contract, which has been extended into next month, the starting salary for school police officers is $27,000. After seven years, officers are paid $40,000 for 10 months of work, Lodise said.

Sample-Oates said former U.S. District Judge James T. Giles, now of counsel with Pepper Hamilton L.L.P., will conduct an investigation into the attacks.

Today, South Philadelphia High principal LaGreta Brown is scheduled to announce more security guards, cameras, bilingual counseling associates, and translators for the school at a news conference.

It would be Brown's first public appearance since the attacks.

South Philadelphia High has a history of racial tensions and is on the state's list of persistently dangerous schools.

In another development yesterday, the Anti-Defamation League offered its help at the school.

"We are very troubled and concerned about these reports," Barry Morrison, regional director of the local chapter of the league, wrote in a letter to Superintendent Arlene Ackerman. "We are interested in learning more about the events that are taking place and would appreciate insights and perspectives you can share."

Meanwhile, a boycott of classes by 50 Asian students over the attacks continued. Seven students required hospital treatment after the attacks.

On Wednesday, about 200 students and community supporters packed the School Reform Commission meeting to decry the racial problems at South Philadelphia and demand action.

Students alleged individual school police officers directed them into the cafeteria, failed to protect them from assaults by African American students, and then told the victims to go home.

Student Duong Thang Ly told the commission that school police officers "are the big problem at South Philadelphia High School."

Ly said the school "should change the security guards so that they will pay more attention to us."

Ly said that when he went to the lunchroom, some African American students had taunted the Asian students.

"Most of the security guards did not care about that and just made a joke to the African American students like it was not important," Ly said. "They did not do anything when they saw kids wander along the hallway during class time, and when students can get out school easily. They did not do a good job, which led to my friends getting attacked inside of the school last week."

The names of the school police officers at the school last week have not been released.

The district has been gathering statements and will review tapes from video cameras. If the investigation determines that officers behaved inappropriately, they will be disciplined, Sample-Oates said.

Lodise, the head of the union, said the way to improve safety for all students and staff is to hire more full-time officers.

"My guys are frustrated," he said yesterday. "It's a very difficult school down there. It always has been."