Pakistan’s Prime Minister, Nawaz Sharif, has urged his countrymen to collectively condemn the lynching of a Muslim student killed for allegedly posting “blasphemous” content on Facebook.

Mashal Khan, 23, was reportedly “stripped, beaten, shot, and thrown from the second floor” of the Abdul Wali Khan University in Mardan, northern Pakistan, last Thursday (13 April).

Thirteen people, including university employees, have been arrested in connection with his murder, according to a local police officer.

“Some employees of Abdul Wali Khan University could be seen among the mob, which has given the investigation a new direction for the time being,” District Police Officer Mian Saeed told media on 15 April. “These employees were very much part of the mob and this is shocking.”

The Deputy Inspector General of Police, Mohammad Alam Shinwari, added that the mob “wanted to burn his body, before police intervened”.

One man responsible for leading prayers at the local mosque refused to do so at Mr. Khan’s funeral, while his replacement was later harassed by locals, according to BBC Urdu.

Blasphemy is an extremely sensitive subject in Pakistan. Around 60 people have been killed after being accused of committing blasphemy since laws prohibiting blasphemy were introduced in Pakistan in 1986. The laws are often abused by those seeking to settle personal scores.

Several Christians have been killed after being accused of committing blasphemy, such as the Christian couple lynched and then thrown into the brick kiln where they worked in November 2014. Meanwhile, a Christian woman, Asia Bibi, has been on death row since 2010 after being found guilty of blasphemy.

Atheists and liberals have also been targeted. In January, five liberal Pakistani bloggers were arrested, but not charged, after accusations they had posted blasphemous content on Facebook and Twitter. Then in March an Islamabad High Court Justice warned that social media in Pakistan would be banned if people continued to use it to “blaspheme”. The Federal Investigation Agency was ordered to launch an investigation.