ROCHESTER, Minn. (AP) _ Teen-agers dressed in punk fashions were among more than 1,000 mourners who packed a church for the funeral of four family members who police believe were hacked to death with an ax by a 16-year-old son.

Two bishops, nine priests and a monsignor presided over a 90-minute Mass Sunday at Pax Christi Catholic Church for Bernard and Paulette Brom and two of their children, 11-year-old Rick and 14-year-old Diane.

David Brom, a high school sophomore described as a gentle boy who wrote poetry but who also favored hard-core punk music, was charged with murder Friday in the deaths of his parents and younger brother and sister.

''We have no idea what all these things can mean,'' said the Rev. Syl Brown, Pax Christi's pastor. ''They have left so many memories,'' he said of the Broms, active members of the church.

''We come here with a spirit of absolute loss. We have no idea what response we can make. But we can see the light their lives has given us,'' he said.

The service included readings by classmates of Diane and Rick, and presentations of symbolic gifts. Among the gifts was a high school basketball trophy given in memory of Diane, who had been a cheerleader for her school's basketball team.

A special section was set aside for teen-agers, including a few with hair dyed black, gold or purple.

After the service, about 100 people braved a raw wind at Calvary Cemetery for the burial. The family's oldest son, Joseph, 19, appeared stoic at the graveside. Joseph, who did not live with his family, has asked to be appointed guardian of David.

Authorities have not yet determined a motive for the slayings. Sheriff Charles Von Wald has said he understands that David had argued recently with his father about a music cassette. The Rev. Jack Krough, chaplain at Rochester Lourdes High School, said friends had recently heard David muse about wanting to hurt his family.

A favorite of David's, according to one friend, is the group Suicidal Tendencies. A song on their latest album describes ''the maniac I'll meet. His love for me is like a father to a son. And now the maniac and I are one.''

Other friends said the teen-ager was always ready with a joke and a smile, and ''wouldn't step on a flower.''

At Lourdes High School, teachers and psychologists are monitoring David's classmates for signs of depression.

''The difficult time is yet to come,'' said Dennis L. Gannon, a licensed psychologist who interviewed about 50 of David's classmates.

Some will sink into depression in 15 to 20 days, he said. Some will withdraw, while others will become unruly and irritable. Some will pull out of the depression in a few days, while others may sink deeper.

''Some of them will have a difficult time working this through,'' Gannon said. ''They'll say things like, 'What's the use, what's the point of going on?'''