BEIJING - Eight people accused by China of involvement in an attack on Tiananmen Square in which five people died had carried out three reconnaissance trips and collected 400 litres of fuel in preparation, state media said.
The accused all came from Hotan in the restive far western region of Xinjiang and were hiding out in western Beijing ahead of the attack, state television said late on Friday.
They had accumulated 40,000 yuan (S$8,000) and a number of knives before driving a Mercedes SUV onto the northern part of the square at midday on Monday, in front of the entrance to the Forbidden City, the report said.
The car ploughed through bystanders on the edge of the capital's iconic Tiananmen Square and burst into flames, killing the three people in the car and two bystanders, in what the government called a "terrorist attack". Forty people were hurt.
Xinjiang is home to the Muslim Uighur minority, many of whom chaff at China's restrictions on their religion, culture and language, though the government says they are granted broad freedoms.
Xinjiang has been wracked by unrest in recent years, blamed by the government on the separatist East Turkestan Islamic Movement which Beijing believes was also responsible for this week's Tiananmen attack.
Rights groups, exiles and some experts say though that there is little evidence of a cohesive extremist movement operating in Xinjiang.
State media have identified the three people in the car as Usmen Hasan, his mother Kuwanhan Reyim and his wife Gulkiz Gini, all from Hotan in the heavily Uighur southern part of Xinjiang.
The five people Beijing police have in custody are also from Hotan, according to state television. Police had previously identified another part of Xinjiang as the hometown of one of the suspects, called Lukqun.
State media said that the eight decided to set up a terrorist group in September, and seven of them arrived in Beijing by SUV on Oct. 7, while one came by train.
On Oct. 23, five of them returned to Xinjiang's regional capital Urumqi, while a family of three remained in Beijing.
Beijing police have said the five people it has in custody were radical Islamists who were planning a holy war. Security has been strengthened in both Beijing and in Xinjiang.
Exiled Uighur leader Rebiya Kadeer told Reuters this week that caution should be exercised over the government's account, adding she did not believe any kind of organised extremist Islamic movement was operating in Xinjiang.
Xinjiang is a sprawling, arid region that borders Central Asian nations that were part of the former Soviet Union as well as Afghanistan and Pakistan.
In 2009, nearly 200 people were killed in the Xinjiang capital, Urumqi, in rioting between Uighurs and the majority Han Chinese.