Under a brilliant midday sun yesterday, two lines of Pittsburgh police officers, wearing black helmets and wielding white batons, marched in lockstep down a field.

They fanned out into a single line of about 50 officers, stretching the width of the field. They raised their batons, moved forward and shouted in unison.

It was the second day of training for police officers who will confront crowds of protesters that likely will descend on Pittsburgh during September's G-20 summit of world leaders.

Police officials asked that the Post-Gazette not reveal the location of the training or the specific tactics being taught because of fears that protesters will use the information to disrupt the summit, which has spawned large demonstrations in other cities.

During the next several weeks, groups of 50 to 60 Pittsburgh police officers will gather at the training site every three days. Most of the Police Bureau's nearly 900 officers will participate.

Instructors from the Center for Domestic Preparedness, a division of the Federal Emergency Management Agency, are teaching the course, which is called Managing Civil Actions in Threat Incidents, or MCATI.

"The MCATI training prepares law enforcement for crowd control and unlawful protest," said Shannon Arledge, a public affairs specialist for the Center for Domestic Preparedness. "It provides officers with the knowledge to handle situations such as this in an effective and professional manner to maintain safety of everyone involved, including the public."

The center, based in Anniston, Ala., offers more than 40 courses for law enforcement agencies and emergency responders. Teams of instructors can deploy across the country to teach the courses, including MCATI.

The center covers the cost of sending instructors.

Police departments involved with providing protection during the Democratic and Republican national conventions, the Super Bowl and the inauguration of President Barack Obama have received the training.

A description of MCATI, posted on the Texas Homeland Security Preparedness Web site, highlights the threat of riots evolving from demonstrations.

"From a small, peaceful assembly to a large, out-of-control violent confrontation, public safety must be prepared to handle the incident," the description says.

"This course provides knowledge and skills in areas such as history of civil disturbance, planning, incident command systems, community and media relations, demonstrator tactics, riot control agents, legal perspectives, doctrinal concepts, crisis decision making, team tactics, force multipliers, and fire ground tactics."

For example, officers learn techniques used by protesters to block city streets.

The Pittsburgh course is running from 8 a.m. to 4 p.m. each day, with classroom lessons in the morning and field training in the afternoon.

Pittsburgh officials declined to discuss details of the training.

"In the interest of national and local security, there are some things that are not for public knowledge and thus are not open for comment," said Diane Richard, a police spokeswoman. "One of our major concerns is protecting our officers. We also want to protect our city, we want to protect our citizens and we want protect our real estate."

In recent weeks, some city officers also have received training from Combined Tactical Systems, a company based in Jamestown, Mercer County, that specializes in crowd-control equipment.

The company sells a range of chemical irritants, smoke munitions and launchers for less-lethal projectiles.

City officials hope to have as many as 4,000 police officers on hand for the G-20, and Mayor Luke Ravenstahl yesterday said the event's total public safety price tag could fall between $10 million and $20 million.

It's unclear where the money will come from, but Mr. Ravenstahl said some of the federal stimulus funds approved by Congress and the president this year could be one source.

Extra officers will be provided by county and state police and possibly police forces from neighboring states.

"We will not sacrifice public safety. We will cut no corners," the mayor said. "I'm confident we will get 4,000 [officers.] We'll figure out a way to get it funded."