AFP/ Karor Lal Esan

Estranged relatives of a Pakistani woman involved in a mass shooting in California spoke Sunday of their shame at her crimes, as former classmates and teachers painted a picture of a quiet, religiously conservative student.

Tashfeen Malik, 29, and her husband Syed Farook, 28, gunned down 14 people at a social services centre in San Bernardino, an act praised by the Islamic State group who hailed the couple as "soldiers" of its self-proclaimed caliphate.

According to her uncle Malik Ahmed Ali Aulakh, who is a former provincial minister, Tashfeen was born in the village of Karor Lal Esan in the central province of Punjab but moved to Saudia Arabia around 1989.

Tashfeen's father Gulzar Malik an engineer, had grown distant from his family and "he never came back even to attend the marriages of close relatives", added Aulakh.

"We are ashamed and shocked about this act done by our niece -- why did she do something so gruesome? We can't believe it," he told AFP.

Malik Omar Ali Aulakh, another of her uncles, added: "We have not kept in touch with Gulzar's family and he avoided contacting us."

The southern region of Punjab from which Tashfeen hailed has long been associated with Sufism, a mystical form of Islam whose adherents worship with song and dance, attend shrines and devote themselves to historic saints -- practices viewed as heretical by more orthodox Muslims.

Indeed, according to Mohammad Jamil, a neighbour of Tashfeen's father, one of Tashfeen's uncles himself was a Sufi devotional singer.

"We don't want Muslims to do such things. Such people should be punished, must be punished," said Jamil, adding: "She has dishonoured Pakistan."

It is still not clear where Tashfeen became radicalised, but by the time she returned to Pakistan in 2007 to pursue a degree in pharmacology at the Bahauddin Zakariya University, she was devoutly religious and wore a veil, according to former instructors.

"She was not outspoken or ultra-modern but she was religious minded, polite and submissive," said Dr Khalid Hussain Janbaz, chair of the pharmacy department.

"I don't think she could have done what they have accused her of, she was a very good student who never created problems for staff or classfellows," added Dr Hussain Shah, an associate professor in the department.

Pakistan's government Sunday issued a statement condemning the attack, even as its interior minister said Islamabad could not be held responsible.

"A country or a national or a religion cannot be held responsible for a crime committed by an individual and I appreciate a wise approach adopted by the US administration on the issue," minister Chaudhry Nisar Ali Khan told reporters in Islamabad.