An off-duty Prince George's County policeman was shot and fatally wounded in the Iverson Mall shopping center yesterday evening during a wild flurry of gunfire that began when he attempted to halt robbers who had just held up a jewelry store.

Officer Raymond Hubbard, 28, a member of the force for two years, was shot at least twice shortly after 6 p.m. as terrorized shoppers and employes shouted, screamed and scurried for cover in the crowded mall in Hillcrest Heights.

Although Hubbard managed to fire his own gun, according to a county police spokesman, it was not known whether any of the three robbers was hit. All were at large last night after reportedly stealing two automobiles at gunpoint to flee from the mall.

Two other persons were injured during the incident, in which 10 or more shots were fired in quick succession and store windows were punctured and shattered, according to police and witnesses.

One of the injured, believed to be a shoe store employe, was shot in the leg. The other victim was cut on the finger by flying glass.

The shooting broke out within seconds after the three robbers, all masked and armed, held up Kay Jewelers on the mall's second level, taking watches and cash.

A woman in the mall corridor apparently saw the robbery taking place. In the words of one witness, she began repeating, as if stunned and talking to no one in particular, "They're holding up the store, they're holding up the store."

The off-duty officer, who was on a shopping trip and wearing civilian clothing, heard the woman and, drawing his gun, ran toward the store, the witness said.

Prince George's County police spokesman Robert Law said Hubbard saw a suspect coming from the area of the store, and he "faced the suspect and challenged him."

Law said two other suspects then emerged from the store, and the officer was caught in a crossfire.

Many persons who did not see the actual shooting said they heard the gunfire. Several said they counted as many as 15 or 20 shots in two separate bursts.

Some shoppers and bystanders threw themselves to the floor. Others screamed, grabbed children and ran. Many hurried into stores along the corridor, clamoring for shelter.

Shots smashed part of the broad plate glass window of a jeans store near the jewelry store and punctured another section of the window.

"Everyone was running," said Gwen Clearwater, an employe of a florist shop at the mall.

The wounded officer, who had been shot in the chest, was taken to Prince George's General Hospital. He died there at 7:22 p.m.

The other two injured persons also were taken to the hospital.

Hubbard is believed to have been the first county police officer killed in the line of duty in two years. On Feb. 2, 1980, officer Antonio M. Kelsey, working off duty as a security guard in a liquor store, was shot when he chased a man suspected of marijuana possession from the store.

The three bandits, all with guns drawn and all wearing ski masks, entered the jewelry store and appeared to be "as nervous as we were," according to assistant store manager Louis von Guggenburg.

The robbers ordered people in the store to lie on the floor. One salesman had been showing a customer watches and the display case was unlocked. One of the robbers jumped over the counter and took the watches from the open case, von Guggenburg said.

After first having trouble opening it, the store official said, the robbers also took money from the cash register.

Von Guggenburg said one robber went out the back of the store and the other two out the front.

He said the gunfire, which he heard but did not see, began "right away."

One of those whose car was taken by the fleeing robbers was a woman who said she was driving slowly behind the jewelry store when a man shouted that he had been robbed. She stopped and he drew a gun, forced his way into the vehicle, ordered her out and drove off.

Dozens of policemen responded and cordoned off the area as rescue workers tended to the injured and police officers searched for evidence and sought out witnesses. Also contributing to this story were Washington Post staff writers Leah Latimer and Edward D. Sargent.