URUMQI, May 25 -- Police in northwest China's Xinjiang Uygur Autonomous Regions have busted 23 terror and religious extremism groups and caught over 200 suspects in May, according to the regional public security department on Sunday.

The groups were busted by police in south Xinjiang's Hotan, Kashgar and Aksu prefectures, where the majority of the population are Muslim Uygurs, according to the department.

More than 200 explosive devices were also seized in the police raids.

Many of the suspects were in their 20s and 30s, who watched terror video and audio through the Internet and electric storages and learned how to make explosives. They exchanged their experiences of making explosives and propagating Jihad through chatting tools, text messages and illegal preaching sites, according to the department.

In 2013, the East Turkistan Islamic Movement (ETIM), listed by the United Nations Security Council as a terrorist group, produced 107 terror video and audio episodes, some of which were spread to China, according to Nuriman Rozi, a senior police officer with the regional public security department.

Many of the terror suspects seized in recent years were instigated by those terror video and audio products to carry out terrorist activities, he said.

Xinjiang started a one-year campaign against terrorist violence on Friday. The campaign will last until June 2015 with Xinjiang as the major battleground.

The region saw its bloodiest day in five years on Thursday when 39 innocent people were killed in a terrorist attack.

The campaign will focus on terrorists and religious extremist groups, gun and explosive manufacturing dens and terrorist training camps.

Legal, procuratorate and public security authorities in northwest China's Xinjiang Uygur Autonomous Region issued a joint statement on Saturday, calling for law-breakers who are involved in terrorist activities to surrender to get lenient punishments.

The statement forbids people to organize, lead or join any terrorist groups. It bans people from implementing or instigating terrorist violence. It also prohibits people from directly or indirectly funding, supporting or harbouring terrorist activities, terrorist organizations and terrorists.

The statement also bans people from manufacturing, trading, transporting, publicizing, copying and holding propaganda materials or electric storages with terrorist violence and religious extremism contents.

Manufacturing, trading, transporting, storing and holding guns, ammunitions, flammable and combustible materials as well as knives under strict control are also prohibited.