Asia Bibi has arrived in Canada hoping to start a new life after her years on death row. But although there is huge relief among campaigners for religious freedom that she is out of Pakistan, her ordeal may not be over.

Islamic extremists have pledged to pursue the Christian woman and kill her for the act of blasphemy of which she was accused and later acquitted. Bibi may spend the rest of her days looking over her shoulder in fear of an international assassin.

Bibi’s backstory is well known after international attention was focused on her case. The former farm labourer was sentenced to death on flimsy evidence in 2010 after being accused of blasphemy in a dispute with Muslim women in her village over a cup of water. Two Pakistani politicians were later killed for publicly supporting her and criticising the country’s draconian blasphemy laws.

She won the support of Pope Francis and Christian organisations around the world. Eventually last October, Pakistan’s supreme court overturned her conviction, triggering violent protests throughout Pakistan and calls for the judges in the case to be killed. The violence was led by the Islamic group Tehreek-e-Labbaik, dedicated to upholding Pakistan’s harsh blasphemy laws.

Although Bibi was freed from prison, she was kept in legal limbo in protective custody while negotiations were under way to find her and her family a new home. Her family went into hiding and claimed they were being hunted down by extremists, going from house to house with photographs.

A number of countries were involved in efforts to find Bibi and her family a safe haven, but Canada quickly emerged as the most likely destination. Two of Bibi’s daughters relocated to Canada earlier this year, while Bibi continued to be held in custody.

No details have been revealed on Bibi’s immediate whereabouts in Canada or where the family might establish a new home. But the months since her acquittal should have provided the Canadian authorities time to work out a plan, which may involve a new identity.

Bibi and her family are expected be kept under the close watch of Canadian security agencies. After the international outcry over her death sentence and the global campaign over her case, any attempt on Bibi’s life in Canada would be catastrophic.

The Catholic church, which has a strong presence in Canada, will be keen to offer Bibi a warm welcome, but some may fear that their churches could become a target by Islamic extremists.

Christians make up only 1.59% of Pakistan’s population of more than 200 million, but about half of those accused of blasphemy in the country are non-Muslims.

According to Open Doors, which monitors Christian persecution around the world, Pakistan’s blasphemy laws “target Christians in particular”.

It said: “The abuses of Pakistan’s blasphemy laws are some of the starkest examples of persecution in Pakistan. They have been devastating for minorities, including Christians, who must always act with caution in case an allegation of blasphemy is raised to settle a personal score.”

Pakistan is number five on Open Doors’ league table of countries in which Christians are at risk.

Last summer, campaigners for religious freedom were dismayed when Imran Khan defended Pakistan’s blasphemy laws while campaigning in the country’s general election.

Critics accused Khan – now Pakistan’s prime minister – of using the issue to win support from religious rightwingers. “Imran Khan is a coward; he is supporting murderers and mob violence. This law is persecuting people, it is not respecting our prophet,” said Shahbaz Taseer, the son of Salmaan Taseer, the governor of Punjab who was killed by one of his own bodyguards after lobbying for Bibi’s release.