A top official in China called an Islamic group "behind-the-scenes" supporters of the attack in Tiananmen Square on Monday, Australia Network News reported.
"Its behind-the-scenes supporters were the terrorist group the East Turkestan Islamic Movement (ETIM) based in Central and West Asia," said Meng Jianzhu, secretary of Central Politics and Law Commission.
Five people were killed after a car drove through bystanders and burst into flames in Beijing's Forbidden City. So far, police have arrested five people they labeled as Islamist separatists.
Hua Chunying, a spokeswoman for the foreign ministry, said the ETIM is "the most immediate and realistic security threat in China." She also said similar organizations "have long been engaged in central, east and west Asia, and have colluded with other international terrorist organisations."
Meng said the attack represents China's victimization of a global terrorism threat and suggested resulting to war, according to Xinhua.
However, a professor at Griffith University in Sydney said ETIM may have connections in Pakistan and central Asian countries though the relations are not certain.
"It's not that China shouldn't be concerned about those (ties), but the core issue is that the linkages have been exaggerated by the Chinese government," said Professor Michael Clarke.
China has also placed blame on Uighur groups -- a Turkic-speaking Muslim population -- for "terrorist attacks" in Xinjiang, though their claims are difficult to confirm. Outside groups also accuse Chinese officials of blowing the threat out of proportion due to cultural and religious restrictions.
Although Xinjiang is a sparsely populated area, it is close to the border of other Asian countries.
A spokesman for the World Uyghur Congress denies that a movement exists in Xinhiang and criticized the security scrutiny Uyhgur people have to deal with.
Within recent months, Chinese authorities have arrested 139 people in Xinjiang in connection to spreading jihad.
