In September 2009, Ji went to Beijing and petitioned the Commission of Politics and Law of the CPC Central Committee. The committee required Dongguan's police department to deal with the issue, and in March 2010, the Houjie's public security bureau gave 100,000 yuan to Ji, according to the statement of Dongguan police.

After receiving the money, Ji expressed gratitude toward the Dongguan police and promised not to petition anymore, said the statement.

Weibo photo shows a man on a wheelchair holding high a white bag at the Beijing Capital International Airport on Saturday.

The explosion caught the attention of netizens on weibo.com, China's most popular micro-blogging platform, with many expressing concerns about social injustice.

"Each unfairly treated person is a potential bomb for the country," wrote Zuoyeben, a renowned micro-blogger who has 6.52 million followers. The post was forwarded more than 7,600 times and commented on more than 6,600 times as of 6 pm on Sunday.

Wang Zhi'an, a commentator on China Central Television, condemned the explosion accident in his micro blog.

"No matter how unfairly you have been treated, if you cross the line, you will be the common enemy of society," Wang said in a post.

On Sunday night, Beijing police reported that they had detained two people who made separate calls to the emergency services hotline 110 on Saturday night, threatening to bomb the airport and a bingo hall. Both were arrested about an hour after the calls. No bombs were found.

Police say the two people had separate grievances and that their bomb threats were attempts to gain attention. Police did not say if the pair's motivations were related to the bombing incident at the airport.

Contact the writers at zhengcaixiong@chinadaily.com.cn and anbaijie@chinadaily.com.cn

Zhao Ruixue in Jinan contributed to this story.