China is to strengthen law enforcement cooperation with Turkey to combat terrorist suspects from the Xinjiang Uygur autonomous region entering the Eurasian country illegally.

From Turkey, the suspects travel to countries in the Middle East to join extreme Islamic forces, Chinese authorities said on Wednesday.

"We will enhance intelligence information exchanges and case investigations with Turkish authorities," said an official source who declined to be identified.

"We will work closely with them to investigate Xinjiang suspects who enter Turkey illegally."

The official also said that police from both countries will consider conducting joint operations to smash cross-border criminal gangs who help Xinjiang terrorists to cross China's borders illegally and assist them in obtaining fake Turkish passports.

In recent years, a number of extremists from Xinjiang have entered Southeast Asian countries illegally, including Thailand, Vietnam and Malaysia.

In these countries, they usually buy fake passports, travel to Turkey and then move on to Syria or Pakistan to join extremist forces and receive military training before returning to China to plan more terrorist attacks, the source said.

In a case that occurred in November, 10 Turkish suspects were accused of crossing the border illegally by prosecutors in Shanghai.

Eleven others, including nine terrorist suspects from Xinjiang, were charged with organizing and taking part in terrorist organizations, according to Global Times in Beijing.

The report said the 10 Turkish suspects allegedly offered fake Turkish passports to the Xinjiang terrorist suspects, who planned to leave China illegally for Turkey through Shanghai Pudong International Airport.

Each of them was charged 60,000 yuan ($9,790) for an illegal passport and immigration clearance, the report said.

It also said the terrorist suspects from Xinjiang planned to enter Turkey illegally, from where they would transfer to Syria, Afghanistan and Pakistan to join extremist forces.

Police found audio and video materials related to terrorism among the suspects when they tried to leave China. The suspects were detained at the scene, the report said.

Under the Criminal Law, if they are convicted of joining terrorist organizations, suspects face prison terms of three to 10 years. If convicted of organizing and leading terrorist organizations, they face sentences ranging from 10 years to life imprisonment.

The case is still being investigated.

Hong Lei, spokesman for the Ministry of Foreign Affairs, told China Daily on Wednesday, "China has been insisting on attacking illegal immigration, and will enhance judicial cooperation with relevant countries to stop such crimes."

Meanwhile, authorities in Xinjiang have announced that people who buy fireworks and firecrackers for Spring Festival must register with their ID cards.

The move is part of efforts to prevent terrorists in Xinjiang from obtaining materials to make explosive devices.

Mei Jianming, director of the Counterterrorism Research Center at People's Public Security University of China, said, "Some practical challenges exist in combating such cases between China and Turkey due to legal obstacles and different legal procedures."

The main task is to "increase mutual trust between the two countries and provide Turkish judicial authorities with solid evidence to prove we are targeting violent terrorists rather than other people," he said.

It is also necessary to enhance judicial cooperation with Interpol and other law enforcement authorities in countries including the United States, Pakistan and Syria to seek their support and assistance, he added.