UPDATED at 3.50 P.M. EST on 2013-05-09
Chinese authorities at a university in the troubled northwestern region of Xinjiang have detained at least three ethnic minority Uyghur students, according to a Uyghur website and an exile group.
Three detained students at Tarim University in Aksu (in Chinese, Akesu) prefecture were named by the Uyghur Online website (Uyghurbiz.net) as Alimjan, Dilshat and Ibrahim, although reports of a further five detentions had been received, with their identities unconfirmed, it said.
Uyghur Online said the students were taken away from Tarim University by police from nearby Aral (in Chinese, Ala'er) city in early May, adding that Ibrahim was detained after being accused of "having overseas contacts."
A lecturer at Tarim University surnamed Li said he hadn't heard of the arrests, but confirmed that security had been tightened in the wake of last month's violence in nearby Kashgar (Kashi), in the region's south.
"They have definitely stepped up security awareness, because there was that incident in Xinjiang a few days back," Li said.
"Our university must obey orders from above, and be on our guard," he added.
Calls to the university principal's office went unanswered during office hours on Thursday.
However, an officer who answered the phone at the campus police station didn't deny the detentions had taken place.
Asked if Alimjan had been detained, he replied: "If you want to know what happened to that individual, you will have to ask our leader."
But he declined to comment further. "The leader isn't here and I can't really talk about this topic."
The April 23 violence in Siriqbuya (in Chinese, Selibuya) township in Kashgar prefecture's Maralbeshi (Bachu) county left 21 dead, and officials have said that 19 Uyghur suspects have been held.
Chinese authorities blamed the violence on Uyghur "terrorists," but rights groups and experts familiar with the region say Beijing exaggerates the terrorism threat to take the heat off domestic policies that cause unrest or to justify the authorities' use of force against the Uyghur minority.
The Munich-based World Uyghur Congress (WUC) has called for more transparency about the case, including information about Uyghurs killed and arrested, as well as details of any terrorist group they may have been linked to.
Sweden-based WUC spokesman Dilxat Raxit said the Maralbeshi county incident had prompted a huge security operation in higher education institutions across the region.
"Students in higher education are being 'disappeared,' and the authorities are refusing to give any reasons for their detention," Raxit said.
He said the WUC lacked clear information on the exact number of Uyghur students detained at Tarim University, however.
"There are reports that eight Uyghurs have been taken away by police, and that no one knows what has become of them," he said.
Tarim University was built in 1958 by the army-backed Xinjiang Production and Construction Corps, also known as the "bingtuan."
The People's Liberation Army production companies, or bingtuan, are units of command that enable Beijing to maintain key areas and exploit rich resources in the largely Muslim northwestern region of Xinjiang, according to exile groups.
Uyghurs say they have long suffered ethnic discrimination, oppressive religious controls, and continued poverty and joblessness, blaming the problems partly on the influx of Han Chinese into the region.
Separately, Raxit said, police in Kashgar's Peyziwat (Jiashi) county had launched an investigation of more than 1,000 residents of Gholtoghraq (in Chinese, Wolituogelake) village after finding handbills written in Uyghur saying "Our dignity cannot be trampled."
He said the authorities had confiscated copies of the Quran and electronic reading devices from more than 260 local people in recent days.
An officer who answered the phone at a police station in Peyziwat county denied that any handbills had been found there.
Meanwhile, an employee who answered the phone at a local hotel said police had stepped up security checks in recent days.
"There are a lot of police patrolling the streets, carrying out more checks," the employee said.
Random interviews by RFA's Uyghur Service showed that security in many other areas in Xinjiang have also been stepped up after the violence in Siriqbuya.
In Urumqi, Xinjiang's capital, ruling Chinese Communist Party cadres would carry out spot checks in a bid to keep tabs on the overall security situation, a Uyghur man told RFA's Uyghur Service last week.
"They come without warning. They come in a group of five or six. They walk around checking," he said.
He said he was informed that similar checks were also taking place in Uyghur-populated areas.
In Kashgar, a Uyghur farmer in Yerken (Shache) county said residents have become used to random checks.
Security officials sometimes lifted the veils covering the faces of Uyghur women for identification purposes, the farmer said.
"There are a lot of incidents, like unveiling the covered-up women and such," he said.
In southern Hotan city, a Chinese immigrant worker said police patrols have also intensified.
"We do not know what happened, but there are police everywhere," he said. "I did not hear about the Siriqbuya incident but now I am used to the police patrols."
Reported by Qiao Long for RFA's Mandarin service, Hai Nan for the Cantonese service and Gulchihre Keyum for the Uyghur Service. Translated by Luisetta Mudie and Mamatjan Juma. Written in English by Luisetta Mudie.