Screen shot from China Central Television's news program shows a suspect of the Kunming train station terrorist attack sitting in the intermediate court of Kunming, the capital city of Southwest China's Yunnan province, Sept 12, 2014. Four suspects stood trial on Friday. [Photo /screen shot from China Central Television]

BEIJING -- A Chinese court on Friday sentenced three men to death and one woman to life in prison for their involvement in a terrorist attack in which 31 were killed at a railway station in Kunming earlier this year.

Iskandar Ehet, Turgun Tohtunyaz and Hasayn Muhammad were sentenced by the Kunming Municipal Intermediate People's Court to death for leading a terrorist organization and intentional homicide, Xinhua learned from the Supreme People's Court (SPC).

In photos: Terror attack in Kunming

Residents mourn the dead in Kunming terror attack

A fourth suspect, Patigul Tohti, has been sentenced to life for participating in the attack as well as intentional homicide.

The Kunming court said Patigul Tohti's criminal acts were extremely severe, but since she was pregnant when she was detained, the death penalty cannot be applied to her according to law.

The court ruled that Iskandar Ehet and Hasayn Muhammad were guilty of recruiting other people to join a terrorist group, while Turgun Tohtunyaz financed terrorist activities.

All three men were found guilty of organizing and plotting violent and terrorist attacks in places crowded with people, the court ruled.

Investigators found that the terrorist organization's members, eight of whom plotted and carried out the Kunming train station attack, had clear roles and responsibilities. Since December 2013, they had been preparing to conduct terrorist activities.

Iskandar Ehet was found to have instilled religious extremism in members and taught them killing methods through audio and video materials demonstrating training methods and how to make explosive devices.

Turgun Tohtunyaz helped fund their terrorist activities several times while Hasayn Muhammad recruited several other members.

In late February, the group plotted in Gejiu, another city in Yunnan, to launch a knife attack in a crowded train station in Kunming. They bought a dozen machetes and daggers and made jihad banners bearing extremist content.

However, two days before the attack, three members of the group, including Iskandar Ehet, were arrested on suspicion of planning to illegally cross the Chinese border to a neighboring country.

After failing to establish contact with Iskandar on March 1, the remaining five set off from Gejiu in a rented car and carried out their attack as originally planned.

Four of them were shot dead on the spot by the police while Patigul Tohti was captured after she was injured by gunshot. The attack caused 31 civilian deaths and injured another 141.

Investigators have found another five suspects linked to the group and they will be tried in a different case.

Public trial of the four began on Friday morning.