The 19 detained in the far-west region, which has been the scene of much violence between the Muslim Uighurs and the majority Han Chinese, were accused of making up and spreading rumors through text messages and the Internet, China Daily reported Monday quoting the region's public security bureau.
The official Chinese media have described the latest incidents last Wednesday and Friday as terrorist crimes in which 35 people died, including 24 civilians and police officers in Lukqun town, and 11 terrorists, who were gunned down at the scene.
Police were quoted as saying spreading rumors can cause as much panic as the terror attacks themselves and lead people to pass on unverified information.
The violence came ahead of the fourth anniversary of ethnic riots in the region's capital Urumqi in which about 200 died. Last April, similar violence claimed 21 lives.
Xinjiang-Uighur is close to the border with Pakistan and Afghanistan. Muslim Uighurs, a Turkic-speaking minority in China, resent being ruled by the majority Han Chinese. China maintains foreign Uighur groups linked to the East Turkistan Islamic Movement are to blame for the trouble in the region and that the movement trains in neighboring Pakistan. However, the World Uighur Congress, based in Stockholm, Sweden, disputes the allegations.
On Sunday, Meng Jianzhu, secretary of political and legal affairs of the Communist Party of China in Urumqi, warned the government will tighten overall measures to strike hard on violent terrorist crimes in Xinjiang to safeguard social stability and the interest of people of all ethnic groups, Xinhua reported. During visits to a police station and city square in Hotan and the Aksu railway station, Meng praised the security forces for helping to maintain ethnic unity.
He urged police to fully implement the recent instructions from the Communist Party's powerful Politburo Standing Committee, calling for a severe crackdown on terrorist crimes, Xinhua said.
An earlier Xinhua report said Chinese President Xi Jinping had ordered the military to restore order in Xinjiang.
Meng was quoted as saying "the atrocity of terrorists in Xinjiang" had outraged the entire nation.
China Daily quoted police as saying Ahmetniaz Stek, a suspected gang leader, allegedly had been organizing its members for extreme religious activities and instigating people to carry out terror attacks since February. Police said the terror group has been raising money to purchase knives and gasoline in recent weeks, the report said.
Zhang Chunxian, party chief of Xinjiang, said anti-terrorism work is extremely important because Xinjiang is facing severe threats from separatists, the report said.
Another party official said even as Xinjiang's economic growth has continued in recent years separatist forces at home and abroad have intensified their activities.
"We will step up actions to crack down on terrorist groups and extremist organizations and track the wanted," he said.
The New York Times quoted advocates of Uighur self-determination and international human rights groups as saying that China's heavy-handed security policies in Xinjiang are only worsening the tensions. A spokesman for the World Uighur Congress said last week's violence was the result of indiscriminate detentions of Uighurs in the area.