Ottawa's Muslim community is struggling to come to grips with an alleged family tragedy that resulted in the deaths of two devout sisters.

Police allege that 32-year-old Asma A-Noor and her 29-year-old sister Nasiba were both stabbed to death in an Ottawa home on Friday night.

They have arrested the women's brother Musab A-Noor , also 29, and charged him with one count of first-degree murder and another count of second-degree murder. Const. Chuck Benoit declined to say which charge related to which victim.

At least one mourner said the sisters' untimely deaths came as a particular shock to a community with which they were heavily involved.

Sheema Khan said Nasiba A-Noor was a well-respected teacher of the Qur'an throughout the region.

She is listed as a staff member at the Tarbiya Learning Academy, an alternative school with a heavy focus on religion, and also conducted private lessons.

It was in that context that she met Khan, who was looking to deepen her understanding of the Qur'an and ultimately memorize the text as A-Noor had done.

The two women would begin their days by talking to each other at 6:45 a.m., Khan said, adding she spoke to her friend the day she died and did not detect anything amiss.

"I loved her," Khan said in a telephone interview. "She's just so humble, and her love for the subject always came through. Even though I talked to her on the phone, I could always tell she was smiling."

Tarbiya Learning co-founder Ghazala Choudhary expressed similar sentiments on social media when reflecting on the woman she hired to teach.

Choudhary said she entrusted her own daughter's education to A-Noor and praised her as both a person and an educator.

"She was a calm, patient and kind individual," Choudhary wrote on Facebook. "I will cherish seeing her sweet smile and exchanging salaams with her every morning. Watching her teach was always so peaceful and I will never forget her compassion towards her students."

Khan said Nasiba A-Noor was also an avid reader, a fact confirmed on her instagram account which lists books, photography, coffee and hiking among her interests.

Much less is known about her sister Asma, who did not appear to maintain social media profiles. But Khan said both sisters were remembered at their funeral as quiet pillars of the local Muslim community and role models for young people.

Khan said a local mosque was filled with hundreds of mourners who were all grappling with shock at the sudden deaths.

She said there were no formal remarks about the sisters' alleged killer, but those in attendance expressed shock that the women's brother is now in police custody.

He has missed two court appearances since his arrest for what Benoit described as "medical reasons," declining to provide further details.

Benoit said the accused is scheduled to appear in mental health court on Wednesday morning.

Musab A-Noor's lawyer, Samir Adam, did not respond to repeated requests for comment to clarify the situation.