About the only thing that competing abortion demonstrators agreed on this weekend was this: A nondescript office park 30 miles north of central Washington is becoming a battleground in their nationwide conflict.

“They say no choice! We say pro-choice!” abortion rights demonstrators chanted Sunday in the Germantown office park.

About 180 people walked in support of LeRoy Carhart, a physician who recently started performing late-in-pregnancy abortions in the office park. It was their kickoff to Summer Celebration of Choice, which will include a week of demonstrations to support the clinic.

On Saturday night, abortion opponents launched their own week-long event, Summer of Mercy 2.0, at a rally in nearby Gaithersburg. Organizers played a video of a Philadelphia woman who recounted a trip to the Germantown clinic about three months ago, when she said she was nearly six months pregnant. She was planning to have an abortion, she said, but was talked out of it by abortion foes outside the clinic.

“I just thank God that I had a healthy daughter,” the woman said in the video, holding week-old Kayden.

In a telephone interview, the woman identified herself only by her first name, Keisha, and said she is 21.

Keisha, who also has an 11-month-old daughter, said she couldn’t get an abortion in Philadelphia when she was nearly six months pregnant with Kayden.

“I was too far along to get one in Philly,” she said. She called Carhart’s office in Germantown, she said, and “they said they’d do it.”

“I am against abortions now,” she said.

In a telephone interview late Sunday, Carhart said the woman was a “plant” by antiabortion forces. He said that his office did talk to her, that she called about 15 times and that he doubted her story. But the staffers were still willing to examine her.

Carhart also said that the clinic will be closed this week. Antiabortion demonstrators had planned to pray outside the office building.

“I didn’t think [patients] needed to be subjected to that harassment,” he said.

The abortion foes also held their own walk Sunday near the clinic, praying as they did so. Later they held a rally in a Gaithersburg church, during which two women — one 18 weeks pregnant and one 23 weeks pregnant — received ultrasound exams that were projected on a 20-by-20-foot screen, said the Rev. Patrick Mahoney, director of the Christian Defense Coalition.

The national abortion debate arrived in Germantown late last year after the arrival of Carhart, portrayed as a hero or a killer, depending on which side is talking. Carhart is one of the few doctors in the nation who openly acknowledges performing abortions late in pregnancies. Because of that, and because he wants to expand services, he has become a top focus of antiabortion groups. His friend and mentor, Kansas doctor George Tiller, was fatally shot by an abortion opponent in 2009.

Carhart travels from his home in Nebraska almost every week to operate his practice. In a wide-ranging interview two weeks ago — his first extensive comments since he began traveling to Maryland in December — Carhart discussed his work and the security measures he has taken since arriving. He said abortion restrictions in other states make him more committed to his practice.

Women who have turned to him for abortions, he said in that interview, have had severe fetal abnormalities. “We’ve helped them. . . . They’d rather die than have these pregnancies,” he said.

Carhart did not attend the walk that was held to support the clinic and its patients. His supporters said he tries to keep a low profile.

But his name and that of his mentor were on full display at the pro-choice rally.

“Dr. Carhart is a hero,” one sign read.

Supporters had written their own messages on the sign. “Thank for keeping us safe,” said one. “Thank you, Dr. Carhart — We Love You!” said another.

The abortion rights activists came as far away as California. Kari Ann Rinker, state coordinator for the Kansas chapter of the National Organization for Women, recalled how abortion foes protested against Tiller’s practice in 1991, during the original Summer of Mercy.

“It totally changed the landscape in our state,” she said, as abortion foes gained political traction.

Mahoney and other antiabortion organizers in Germantown said that by going after controversial figures such as Carhart, they seek to chip away at abortion laws and procedures with the ultimate goal of overturning Roe v. Wade.

“He’s the most well-known abortion doctor right now,” Mahoney said of Carhart. “He’s out front, and I think he enjoys that role. . . . What we do is work on the outer edges and work in.”