SEPTA will add 30 officers to the 60 already on duty between 2 and 5 p.m., spokesman Richard Maloney said. The agency will pay overtime to current officers to provide the extra protection, Maloney said, a move that will cost about $17,000 more per week.

Crime data show that serious crime on SEPTA property is up 81 percent between 2004 and 2007. Jim Jordan, head of public safety for SEPTA, said the vast majority of complaints concern teenagers using the system after school.

"Schoolkids can be very disruptive and appear very threatening," Jordan said, adding that there are fewer problems in the summer when there are fewer teens going to school. "A major concern for us is people feeling safe."

Yesterday's move follows three recent attacks in or near subway stations, including the March 26 death of Sean Patrick Conroy, 36, a Starbucks manager in Center City. He was beaten and kicked on the Market-Frankford subway concourse at 13th and Market Streets and suffered a fatal asthma attack during the assault.

Five Simon Gratz High School students are charged as adults with murder in Conroy's death.

Conroy's father, Steve Conroy, said he was glad to see SEPTA shore up policing but called it "a day late and dollar short" for his son.

"If they're doing it on overtime, that says to me it is a temporary thing that eventually will be forgotten," Conroy said. He said extra police protection needs to be sustained.

In another assault, Tyesha Tazwell, 23, was thrown to the ground, kicked, and punched by a gang of 12 youths and adults Wednesday night as she was walking through the Gallery underground near Eighth and Market Streets. Five people, ranging in age from 16 to 20, were arrested and charged.

On Friday night, three men wearing black wigs assaulted and robbed a 30-year-old Southwest Philadelphia man of $20 as he rode the Market-Frankford line after boarding a train at 13th Street. No one has been arrested in that attack.

Anthony Black, 43, rides that line every evening at 5:30 to his night job at a market research company in Center City - and then again at 10 p.m. when he heads home to Northern Liberties.

At 6-foot-3 and 225 pounds, he doesn't scare easily, he said yesterday. But even he doesn't like the concourse that connects the Market-Frankford Line to City Hall and the Broad Street Line. So he was happy to hear he will be seeing more officers around.

So was Renea McLaughlin, 44, of Sicklerville, who had just ridden the Broad Street Line from Snyder Avenue to the City Hall stop yesterday.

"It's a good thing," she said when told of the plan for more police presence along her commute. But the additional officers won't cause her to change her routine, McLaughlin said.

That involves avoiding the tunnel that connects the Broad Street Line to Market Street, where she catches a bus for home. Instead, she heads upstairs and walks several blocks outside.

"I won't walk through that tunnel anymore," the Verizon employee said. "I just decided it's not worth the risk."

Jordan, SEPTA's public safety head, said the added patrol officers will be in uniform and an undercover detail could be added if needed. The Philadelphia Police Department has also increased patrols of SEPTA facilities.

SEPTA took its action at the request of Christian DiCicco, a SEPTA board member who represents Philadelphia and is running for election to the state House. DiCicco is the the son of City Councilman Frank DiCicco.

Appearing at a SEPTA capital budget hearing yesterday, Christian DiCicco also urged that SEPTA permanently hire 50 more police officers over the next two years, increasing the force to about 300 officers, at an annual cost of about $2.85 million. He also called for SEPTA to accelerate its plan to install cameras and other security equipment in subway stations.

"The problem is the severity of the recent attacks. . . . The perception is out there that the system is unsafe," he said. "We need to calm those fears. If our riders don't feel safe, we're going to lose significant revenue."

SEPTA spokesman Maloney said that board action would be required to hire additional police officers and that agency managers would look into speeding up the installation of cameras. The current plan calls for cameras and other security equipment to be in place in all stations by 2012, at a cost of $54 million.

SEPTA officials said in a statement yesterday that, despite the recent attacks, they "remain confident that the SEPTA transportation system is safe."

As she descended the steps to the subway at Broad and Vine Streets shortly before 6 p.m. yesterday, Brittani Mandly, 19, of Germantown, wondered why reinforcements were not added long ago: "It's about time."

Inquirer staff writer Diane Mastrull contributed to this report.