Oscar Pistorius's girlfriend was standing in a toilet cubicle and facing the closed door when she was hit in the right hip by the first of four hollow point bullets fired by the double-amputee athlete, a police ballistics expert testified on Wednesday at Pistorius's murder trial.

Reeva Steenkamp then fell back onto a magazine holder in the cubicle and was struck in the right arm and head by the last two shots fired from the 9 mm pistol through the door as she crossed her arms over her head to protect herself, Capt. Christiaan Mangena said. He testified that he believed the second bullet shot missed Steenkamp and ricocheted off a wall inside the cubicle and broke into fragments, which caused bruising on her back.

Mangena concluded, through his analysis of the shooting scene and wounds on Steenkamp's body from post-mortem photos, that one bullet went through Steenkamp's left hand before penetrating her skull as she held it over her head. The policeman said he couldn't determine the order of the last two shots.

Pistorius, 27, is charged with premeditated murder in Steenkamp's shooting death on Feb. 14 last year and faces 25 years to life in prison if convicted. He says he shot Steenkamp, 29, by mistake through a locked door in his bathroom because he thought she was a dangerous nighttime intruder in his home.

Pistorius says Steenkamp went to use the toilet during the night without him knowing, but prosecutors maintain he killed her after a loud argument that caused her to possibly flee and hide in the toilet area.

Police ballistics expert Mangena said the bullet that struck Steenkamp's skull broke into two fragments, one of which exited her head and struck the wall behind her. The first shot into the right hip broke Steenkamp's hip bone, Mangena said.

"I'm of the opinion that after this wound was inflicted, my lady, she dropped immediately," Mangena said, addressing the judge in court under questioning from prosecutor Gerrie Nel. Steenkamp slumped into a "seated or semi-seated position" on top of a magazine rack in the cubicle, where she was hit another two times.

"She ended up with her head on top of the toilet seat, and the lower part of her body on the rack, Mangena said.

Pistorius fired from a distance of at least 60 centimeters and no further than a wall behind him, about 3 meters away, Mangena said. Mangena also described the impact of the type of bullets in Pistorius's gun, which were designed to cause maximum damage, he said.

"It hits the target, it opens up, it creates six talons, and these talons are sharp," Mangena said. "It cuts through the organs of a human being."

He noted the Black Talon brand of ammunition was often used for self-defense because while it caused significant damage to a human target, it was less likely to penetrate the first target and hit other people.

Mangena also said he conducted shooting tests to try to pinpoint the location from which the bullets were fired by Pistorius in the bathroom, based on where the cartridge cases were found. However, in his tests, he said, the cases fell at different angles. He also noted that the cartridge cases at the scene of Steenkamp's shooting could have been "moved or kicked around" during the investigation.

He said Pistorius was probably on his stumps when he fired, supporting the athlete's statement that he was not wearing his prosthetic limbs when he opened fire.

Prosecutor Nel also asked Mangena to comment on a 2012 incident in which Pistorius allegedly fired his gun out of the sunroof of a moving car. The athlete faces a firearms charge in that case, as well as two other firearms charges.

Mangena said firing a shot in such circumstances was dangerous.

The bullet leaves the barrel at around 280 meters (900 feet) a second, and will travel upward, then stop and fall to the ground under the force of gravity and wind deflection, he said.

"The bullet can still kill a person," Mangena said.

Around 200 Taiwanese students and activists were locked in a tense standoff with police on Wednesday after they stormed the parliament in a bid to thwart government efforts to ratify a contentious trade agreement with China.

Tearing down signboards and chanting anti-government slogans, protesters unexpectedly broke through security barriers and took over parliament's main chamber late on Tuesday, in the first such occupation of the building in the island's history.

The protesters — mostly young students — have barricaded the entrance with ceiling-high piles of armchairs, blocking hundreds of policemen who attempted vigorously early on Wednesday to push their way in to end the occupation.

The protesters are vehemently opposed to what they term illegal moves by the ruling Kuomintang party to pass the trade pact with China, the island's biggest trading partner, and are demanding that it be reviewed clause-by-clause.

"The trade pact must not be approved without careful deliberation and scrutiny in parliament," a student leader said.

The pact — designed to further open up trade between Taiwan and China, which split 65 years ago after a civil war — passed the first hurdle in parliament on Monday after it was approved by a joint committee despite opposition concerns that it could hurt small service companies and damage the Taiwanese economy.

The committee's approval — the first of three ratifications needed to pass the bill — sparked a brawl between rival lawmakers and provoked three opposition Democratic Progressive Party legislators to stage a 70-hour hunger strike.

The China-sceptic DPP has pledged to mobilise supporters when parliament holds a full session on Friday for a second review of the bill.

The pact is one of the follow-up agreements to the sweeping Economic Cooperation Framework Agreement signed in 2010 to reduce trade barriers.

Under the deal, China will open 80 service sectors to Taiwanese companies, while Taiwan will allow Chinese investment in 64 sectors.

Cross-strait ties have improved markedly since President Ma Ying-jeou of the China-friendly Kuomintang came to power in 2008 pledging to strengthen trade and tourism links. He was re-elected in January 2012.

But China still considers Taiwan as part of its territory awaiting reunification — by force if necessary.

Police in China's restive western region of Xinjiang shot dead an armed assailant for attacking an officer, who later died, state media said on Wednesday.

The suspect used unspecified weapons to injure a police officer in the city of Urumqi on Monday night, the official China News Service reported. Officers who arrived at the site shot the attacker dead.

The injured officer, who was 29, later died, the news agency reported.

The report did not identify the ethnicity of the assailant, but it was the latest in a series of attacks pointing to growing unrest in the sprawling region.

Xinjiang is home to a simmering rebellion against Chinese rule among parts of the native Turkic Uighur (pronounced WEE'-gur) population who chafe against Beijing's rule. Recent clashes, including an attack on police last month, have left dozens of people dead.

Officials have also said an attack March 1 at a train station in the southern city of Kunming, hundreds of miles outside Xinjiang, was carried out by Xinjiang separatists.

That attack left 33 people dead, including four assailants who were killed by police.