An 18-year-old man from a village in Kashgar prefecture in the Xinjiang Uygur autonomous region, who was reportedly influenced by religious extremism, is the alleged mastermind behind the murder of an imam from China's largest mosque, local police said on Sunday.

Three people attacked and killed Juma Tayier, 74, after he performed the routine sunrise prayer at 6:58 am on July 30, at Id Kah in Kashgar, the most influential mosque in Xinjiang. Two suspects were shot dead at the scene and the third, Nurmemet Abidili, 19, was taken alive.

Police arrested Aini Aishan, 18, in Xinjiang's Hotan city two days after the murder for allegedly plotting the attack.

Aini has worked on construction sites in Hotan since he graduated from junior high school in Kezilesu township in Kashgar's Jiashi county in October 2012. Police said Aini came in contact with a local religious extremist group in January 2013 and obtained violent terrorist videos as well as prohibited religious publications so he could preach to other people.

In January, Nurmemet, who is also from Kazilesu, called to ask Aini where he could learn about Islam, and Aini told Nurmemet to come to Hotan. He then became Nurmemet's instructor, showing him the terrorist videos and teaching him about religious extremism.

According to Xinjiang Daily, Aini knows little about the Quran — the holy book of Islam — and admitted to the police he skipped many parts because he could not understand them.

In June, another man from Kazilesu traveled to Hotan and told the pair he wanted to carry out "holy war". Ac cording to the report, Aini told the two to go back to Kashgar to prepare to kill Juma so they could earn places in heaven.

Aini believed Juma twisted the meaning of the Quran and that killing someone so influential would create a large impact, the report said.

Nurmemet said he previously knew nothing about holy war and never thought about killing anyone until he watched the terrorist videos and read books on religious extremism in Hotan, Xinjiang Daily reported.

He then became very excited and determined to carry out holy war. He believed Juma had to die and said his mind turned blank when he attacked the elderly imam with an axe.

Before Nurmemet left home to go to Hotan, his parents warned him not to get involved in bad things, so he never spoke to them about the religious extremist group or the plan to murder Juma, the report said.

In Xinjiang, more than 200 terrorist suspects were arrested in May. Most were from the post-1980s and '90s generations who use social media or videos stored in multimedia devices to promote religious extremism as well as share techniques, such as how to make explosives, police said.

"Young people in rural areas who are less educated are the group that are relatively easiest to be manipulated," said Ma Pinyan, a senior anti-terrorism researcher at the Xinjiang Academy of Social Sciences. "Poor education can lead to unemployment, which can make them feel they have few opportunities and they become dissatisfied with society. Those young people also know little about Islamic knowledge or doctrines, which is taken advantage of by religious extremists."