(CNN) -- Several explosions rocked a county in northwestern China early Sunday, killing at least two people, state-run media reported.
The explosions, which occurred between 3:20 and 4 a.m., blasted the 400-population Kuqa County in China's remote Xinjiang Uighur Autonomous Region, which borders Tibet to the south, state-run news agency Xinhua reported.
They came less than a week after an attack in the same region killed 16 police officers and injured 16 more, forcing authorities to step up security.
Authorities had tightened security in the Xinjiang region with increased security checkpoints on roadways and around government buildings, schools and hospitals after Monday's attack in the border city of Kashgar, also known as Kashi. Watch how the region has become volatile »
In that attack, two men crashed a dump truck into a group of police officers before throwing at least five homemade explosive devices into their barracks.
Police arrested both attackers and identified them as two Uighur men, ages 28 and 33, Xinhua reported.
Police suspect a terrorist plot behind the attack.
The Xinjiang Uighur Autonomous Region, also called East Turkistan, is home to a Sunni Muslim ethnic minority. Uighurs in Xinjiang are supposed to enjoy regional autonomy, as guaranteed by China's constitution, but some seek independence.
Millions of Han Chinese, the country's dominant ethnic group, have migrated into Xinjiang over the past 60 years, prompting complaints that they dominate local politics, culture and commerce at the Uighurs' expense.
The dissatisfaction has turned violent at times, including several sometimes-deadly bus bombings in 1992 in the provincial capital, Urumqi. Officials blamed such incidents on Uighur groups who seek an independent Muslim state.
China insists that only a small minority of Uighur support the separatists.
The regional public security department said it received intelligence suggesting that the East Turkistan Islamic Movement planned to make terrorist attacks between August 1-8, Xinhua reported.
The movement wants an independent, self-governing Xinjiang.
Last month, police said they had cracked five terrorist groups in the autonomous region where Monday's attack happened. Authorities said the groups were plotting to sabotage the Olympics, Xinhua reported.