There was a heavy police presence as hundreds of family, colleagues and patients attended Monday's burial service in Amherst, New York.

The funeral took place as it emerged Dr Slepian's name was on an Internet hit-list.

Tom Carver: Doctor shot at home whilst talking to wife

He was killed at his home by a single bullet fired through his kitchen window by a high-powered rifle.

The Planned Parenthood Federation of America said Dr Slepian had been named on an Internet hit-list of abortion providers and supporters.

Dr Slepian was not afraid of activists

The Website, which features animated dripping blood on the title page, lists hundreds of physicians, judges and prominent feminists across the United States.

Dr Slepian's name has a line running through it, which according to the site's authors indicates a "fatality".

The site encourages readers to submit personal information on abortion supporters, including addresses and phone numbers, the ages of their children and the schools they attend.

Rev Donald Spitz: "Doctor Slepian is now reaping what he sowed"

The Website features photos of aborted foetuses and has links to the Army of God.

Letters signed by the shadowy organisation claimed responsibility for the 1997 bombings of a gay bar in Atlanta and an abortion clinic, and for this year's fatal Birmingham abortion clinic bombing.

Dr Slepian, a target of protesters for more than a decade, is the third abortion doctor to be murdered in the US in the past five years.

Jane Hughes reports on fears of an escalation in anti-abortion violence

Canadian police believe there is a link with attacks on four other doctors in the area over the last four years.

Politicians including President Bill Clinton have condemned the killing, and New York Governor George Pataki has called for the culprit to be executed.

Jane Hughes in New York: "Link with past attacks"

But Reverend Donald Spitz, the director of Pro-Life Virginia, hailed Dr Slepian's killer as "a hero."

"Someone else who loved the babies that he planned on killing stopped the serial murderer," Rev Spitz added.

Clinton letter read out at funeral

A mourner at Dr Slepian's funeral

Relatives and friends attending Dr Slepian's funeral service hailed him as a compassionate doctor who cared for his patients and family.

A letter from President Clinton, read at the funeral, said: "Violence in our society hurts all but few have had to endure its effects so personally."

Sympathisers left scores of flowers, notes and signs outside the doctor's office. One read: "We Won't Go Back - Defend the Right to Abortion."

A photo of a smiling Dr Slepian cradling a baby he delivered was taped to the door with a sign saying: "Respect Life Don't Murder Doctors.''

In a 1994 television interview, Dr Slepian said he was not afraid of the anti-abortion protesters.

"I am not afraid of them. I am not afraid of the violence," he said. "I fear for my family, my children. I think if I wasn't around what they would go through."