The brother of a Canadian cardiologist gunned down in Pakistan in front of his wife and two-year-old son says Mehdi Ali Qamar had just arrived in Pakistan to do volunteer work at a hospital.

Police say two gunmen riding a motorcycle shot Qamar 10 times at close range in the town of Chanab Nagar, adding that Qamar's wife and son were not harmed.

Hadi Ali Chaudhary said his brother and his family arrived in Pakistan several days ago from their home in Ohio and planned to treat patients at the Tahir Heart Institute in Rabwah.

Chaudhary said Qamar, his wife and two-year-old son were visiting the graves of his parents when he was killed on Monday.

Qamar, 51, who had been living in Ohio for about 10 years, will be flown back to Canada for burial in Toronto.

A Foreign Affairs spokesman says they are in contact with local authorities to gather more information.

Qamar knew dangers he faced

Police have said they don't have a motive for Qamar's slaying, but the family said he was killed for being a member of the Ahmadiyya Muslim Jama'at Canada community.

"The government of Pakistan, they made a law against our community that these are non-Muslim, and because of that law … anybody can kill the person who is non-Muslim," Chaudhary said.

Qamar knew of the danger he faced, his brother said, but regularly went to the region for three or four weeks at a time to volunteer at the hospital, visit family and help the poor.

"That's the kind of generous man he was," Chaudhary said.

The Qamars' eldest son had remained in Ohio, and his other son was in Pakistan but not with his parents at the time of the shooting.

Jason Elsea, from the Ahmadiyya Muslim community in Columbus, Ohio, said Qamar lived in Pickerington and had a practice in Lancaster. Qamar had recently taken a sabbatical to volunteer at the heart hospital.

"Many doctors from the U.S. have visited this hospital to help those in need," Elsea said in a statement.

Dr. Abdus Malik, Qamar's friend and hospital colleague in Ohio, said he had made summertime trips over the past several years to do work at the institute.

"And this time they wouldn't let him come back," he said. "Just because the difference in our faith, they want to kill us."

Sect targeted by extremists

Ahmadis follow the self-proclaimed prophet Ghulam Ahmad and consider themselves Muslims, but are forbidden from presenting themselves as such by Pakistani law. They have long been targeted by Islamic extremists, and earlier this month a member of the sect accused of blasphemy was shot dead by a gunman who walked into the police station where he was being held.

Saleem Uddin, a spokesman for Ahmadiyya Jamaat Pakistan, an organization representing Ahmadis, condemned the "brutal murder of this doctor who served fellow human beings without discrimination."

He said the attack was part of campaign against Ahmadis and the heart institute, and came after leaflets appeared declaring that treatment there was forbidden by Islamic law.

"In order to put a stop to murders in the name of faith it is essential to put a ban on hate-promoting literature, and those who are legitimizing murder of innocent people should be brought to justice," he said.