Chinese police say they have held a suspect in connection with a suicide bombing on Thursday which killed 39 people.
More than 90 others were wounded.
The attack at a vegetable market in Urumqi in far western China was the deadliest in the region for years. Two vehicles drove into crowds, throwing explosives.
Police say the other four suspects died in the attack.
The region has a large Muslim Uighur minority. Many say they are not allowed to freely practise their religion and culture.