A militant Islamist organisation has said last month's deadly car crash in Beijing's Tiananmen Square was a "jihadi operation", and predicted more violence, according to the US-based monitoring group SITE.

A video posted online by the Turkestan Islamic Party showed the organisation's leader Abdullah Mansour speaking in Uighur, said the Washington-based SITE Intelligence Group, which monitors jihadist forums.

According to Chinese police, three Xinjiang Uighurs drove a car loaded with petrol canisters into the gate of the Forbidden City on October 28. The incident left two people dead, besides the three in the car, and 40 injured.

In an eight-minute message, Mansour, his face obscured, described whose who carried out the attack as "mujahideen", SITE said. He warned that Uighur fighters would target the Great Hall of the People on Tiananmen Square, where the ruling Communist Party holds its meetings.

Mansour was quoted as saying: "Chinese unbelievers, know that you have been fooling East Turkestan for the last 60 years, but now they have awakened.

"The people have learned who is the real enemy and they returned to their own religion. They learned the lesson."

It was unclear if the video posted online includes an explicit claim of responsibility, and there has been no mention of it in Chinese state media.

Some security analysts believe the Turkestan Islamic Party is the parent of the East Turkestan Independence Movement (ETIM), a group that China and the United States have placed on terror lists. Others say both names refer to the same group.

China's top security official recently said that ETIM was the "behind-the-scenes" supporter of last month's fatal attack in the symbolic heart of the Chinese state.

The Xinjiang region in China's far west is home to the mainly Muslim Uighur ethnic group, many of whom call it East Turkestan.

Beijing has pointed to violent incidents in Xinjiang as evidence of rising extremism among the Uighur ethnic minority. But information in the region is tightly controlled, and Uighur organisations complain of cultural and religious repression.