Sheila Fullerton, a teacher at St. Mary's Grammar School in the town of Magherafelt, said about 40 boys and girls aged 16 and 17 approached her asking to mount the protest. "They feel strongly this something they must do," she said.
Irish abortion rights groups welcomed the clinic's opening but said they wouldn't mount counter demonstrations because that would only encourage potential violence and the intimidation of pregnant women outside the clinic.
About 50 women per year do receive abortions in Northern Ireland hospitals after doctors deem their pregnancies pose a sufficient risk to their health.
Goretti Horgan, leader of a Belfast-based group called Alliance for Choice, said while the clinic wouldn't technically offer any increased access to abortion, it would encourage women to seek the abortion pill who previously had to seek state-funded services through their local doctor.
Horgan said local doctors might be opposed to abortion themselves or fearful of being targeted by protesters or lawsuits. She said this meant women with life-threatening conditions often still found themselves flying to Britain as a less difficult option.
"The main need for the clinic is for the women who are ill or very distressed and have a right to a legal abortion here. For those women I think it's awful that they put those women on a plane, with their medical notes under their arms. It's scandalous," she said.
Like almost all Northern Ireland politicians, Health Minister Edwin Poots says he doesn't want the clinic in Belfast but it can operate as long as it observes all existing laws.
"If they break the law, they will be prosecuted," he told lawmakers.
The clinic's legal inability to offer any abortion option to women more than 9 weeks pregnant means that those seeking abortions because the fetus has been diagnosed with fatal abnormalities still must travel to Britain.
Ruth Bowie, spokeswoman for an Irish group called Terminations for Medical Reasons, said doctors can detect such problems only once the fetus is at least 12 weeks old.
Bowie said Northern Ireland's abortion laws mean the clinic "will be of no help to the women north and south who are facing the trauma and upset of fatal fetal abnormalities. Women and men in this situation continue to be forced to travel away from family, friends and their homes at the worst time of their lives."
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