CONCORD, Calif. (AP) _ Police officers spent the weekend riding commuter trains and passing out fliers, in an effort to find someone who might help them solve a Japanese exchange student's murder.

Masakazu Kuriyama was shot twice in the back of the head outside a Bay Area Rapid Transit station Thursday night. He died in a hospital Saturday with his parents by his side.

''We have some new leads and we're following those as well as some old ones,'' police Officer Joseph Kreins said Sunday.

He declined to elaborate, but said officers spent the past three days riding BART trains, trying to locate witnesses.

Police believe the shooting was a robbery gone wrong, but are not ruling out the possibility of a hate crime, Kreins said. Kuriyama had his Sony Walkman, $140 in cash and his credit cards when officers found him face down in a grassy area next to the railroad tracks.

His death is the latest in a string of attacks against Japanese visitors that have shocked and angered their countrymen at home.

Two Japanese students were beaten and robbed in San Francisco in early August.

Last May a Baton Rouge, La., man was acquitted of manslaughter after he fatally shot a Japanese teen-ager who had gotten lost looking for a Halloween party. The man said he thought he was protecting his family from the 16-year- old stranger, who had come running up to him.

Japanese media, which had reacted with uncharacteristic anger to the Louisiana slaying, made Kuriyama's death their major story Sunday.

Television news stations led with on-the-scene reports from Concord, and although Kuriyama's death came too late to be reported in Sunday's newspapers the shooting was prominently reported in Saturday papers.

''Once Again, A Japanese Exchange Student Is Shot,'' read a banner headline in the national Mainichi newspaper.

Kuriyama's parents issued a statement saying they harbor no bitterness against the United States for their son's death.

Kuriyama, who had been in the United States for a year studying English, loved the country and had asked to stay another year, said Steve Durkee of his host family.

Kuriyama had just started work at a Western clothing store in San Francisco, and he left there about 10 p.m. Thursday, police said.

He normally would have gotten off the train at a different station to return to his host family's house in Alamo. But friends told the Contra Costa Times newspaper that he got off in nearby Concord instead to pick up a friend's bicycle because his had recently been stolen.

The grief-stricken friends said Kuriyama promised to call for a ride when he got to the station but either forgot or never got a chance.