It was unclear what charges had been brought against the defendants.
Hou Hanmin, the director of the Xinjiang government information office, refused to say what the charges were, but said they had been published in local newspapers.
The internet has been blocked in Xinjiang since July and local newspaper websites cannot be accessed from outside the region.
The court in Urumqi also sentence five people to death with a two-year suspension - a sentence that is usually commuted to life imprisonment - and jailed another eight people for life, according to a statement reported by the Reuters news agency.
Nine people were executed in November over the riots, and eight others were sentenced to death earlier this month.
Following the July riots, mobs of Han Chinese roamed the streets of Urumqi staging attacks on Uighurs in revenge.
Thursday's sentencing comes days after a decision by the government of Cambodia to deport 20 Uighurs who had sought asylum there after fleeing the unrest in Xinjiang.
They were deported last week to China, a decision criticised by human rights groups and the US government.
The UN refugee agency also condemned the deportations.
The Cambodian government said the Uighurs were being deported for breaking immigration laws and entering Cambodia illegally.