The man, Ji Zhongxing, said he had been paralysed after being beaten by security agents in China in 2005.

No one was killed in the blast, although Mr Ji suffered injuries and was taken to hospital.

If found guilty, he could face three to 10 years in jail for endangering public safety, state media report.

Photos in state media showed Mr Ji giving evidence from a hospital bed to the court.

According to the verified microblog feed of the Beijing court, Mr Ji said he did not deliberately detonate the home-made device and that he regretted his actions.

His lawyer, Liu Xiaoyuan, said that Mr Ji "took out the explosives at the airport to raise awareness about his plight", and "detonated the explosives by mistake" when he was putting them down.

"This is a case of an explosion caused by negligence," he wrote on his microblog.

Prosecutors said that Mr Ji had endangered public safety and should be held criminally responsible for the explosion, news agency China News Service reported.

The 34-year-old from central Shandong province had been petitioning the authorities over his lower limb paralysis, which he said was caused by a beating from several security officers in Dongguan, south China's Guangdong Province, in 2005.

Mr Ji was also apparently dissatisfied with the way his complaints against the authorities had been dealt with.

His case drew widespread sympathy from the Chinese public, the BBC's Martin Patience in Beijing reports.

While an extreme example, it exposed the immense frustrations many feel in China when trying to seek justice, our correspondent adds.

There were reports of petitioners gathering outside the court, expressing support for Mr Ji and asking for their grievances to be considered.

There was also considerable sympathy for Mr Ji on China's microblogs.

Sina Weibo user nymfj wrote: "I hope he is pardoned", while user Let Go of Your Arrogance asked: "Has anyone investigated the case where Ji Zhongxing was beaten?"

Sina Weibo user Old Yip's Comments wrote: "Ji Zhongxing is a man pushed to the brink by Chinese society. From media reports, you can see that he did not want to harm anyone with his 'explosion', he only wanted to gain attention for his plight. I recommend he is given a reprieve. At the same time, the Guangdong government must give him compensation, and support him for the rest of his life."

However, some users argued that Mr Ji should be punished.

"These cases show that terrorism must be opposed everywhere... it must all be dealt with in accordance to the law," user Zhang Yiwu wrote.