Security authorities in Xinjiang have arrested seven suspects allegedly involved in the deadly attack at a train station in the region's capital, Urumqi.
The knife and suicide bomb attack on May 1 killed three people, including two of the suspected attackers, and left 79 injured.
Authorities in the western region had said the attack was carried out by religious extremists. Muslim Uygurs make up a big minority of the population in Xinjiang.
The suspects, who are being held pending further investigation, were arrested on Wednesday in Jimsar, a prosperous township in a rapidly developing economic zone north of the Tianshan mountains, the state-run Global Times reported.
The suspects took refuge in Jimsar to exploit its "geographical convenience" to flee the region, the Global Times report said.
Most come from the same family, and include two brothers, a cousin and the wife of Sedirdin Sawut, a 39-year-old suspect who allegedly took part in the attack, brandishing a knife before detonating a suicide bomb.
Last week a radical Islamist group called the Turkistan Islamic Party claimed responsibility for the Urumqi train station attack and threatened more attacks aimed at securing Xinjiang's independence, Reuters reported.
Similar attacks have occurred in several large cities this year, increasing tensions between China's ethnic minorities and the majority Han population, with security precautions being upgraded in almost every region.
Security checkpoints with metal detectors will be set up at bus stations in Urumqi, according to iyaxin.com, a regional news website.
After the Urumqi attack, public security authorities in Xinjiang posted a 100,000 yuan (HK$125,000) reward for information leading to the suspects' arrest.
A government anti-terrorism expert in Beijing told the Global Times that family terror cells had become a trend in the volatile region. The expert said the group in the Urumqi attack came from three families, but the "members were bonded by blood".
The expert went on to note that as authorities intensified anti-terrorism activities in Xinjiang, the extremists were becoming increasingly cautious.
A survey by the Beijing News showed that many provinces and regions held major anti-terrorism drills, with security levels increased significantly, after a knife attack in March at a railway station in Kunming claimed the lives of 33 people, including four of the attackers. Officials blamed that attack on Uygur separatists from Xinjiang.