A series of bombs packed with ball bearings exploded outside a provincial headquarters of China's ruling Communist Party on Wednesday, killing at least one person days after a fiery attack in Tiananmen Square.

Police and state media gave no possible motive for the blasts in Taiyuan, capital of the northern province of Shanxi. Disgruntled citizens have staged several incidents elsewhere in the country in recent years.

The bombings came a little over a week after a fatal car crash described by authorities as a "terrorist attack" at the symbolic heart of the Chinese state, and days ahead of a highly anticipated meeting of top party leaders in Beijing.

"There were several explosions caused by small explosive devices near the party provincial commission in Taiyuan," local police said on a verified social media account.

Eight "explosive sounds" were heard, the official Xinhua news agency said, adding that police "discovered ball bearings and explosive devices made using electric circuitboards" at the scene.

Metal fragments such as ball bearings and nails are used in bombs to increase injuries, and Xinhua cited police as saying the finds indicated the blasts were "self-made bombs".

Protests in China -- on a host of issues including local corruption, land seizures, environmental policy, and labour rights -- are estimated to top 180,000 a year, even as the government devotes vast sums to "stability maintenance".

Legal paths for pursuing justice are limited in the one-party state, as courts are subject to political influence and corruption, and citizens who lodge complaints against authorities often end up in detention.

The street where Wednesday's explosions happened was the scene of a protest by some 200 laid-off workers last week, according to microblog postings.

One person was confirmed dead in the blasts, another was severely wounded and seven slightly hurt, a provincial government news portal said, citing police.

"Witnesses said that there were seven sounds of explosion that lasted several minutes and were very powerful," media company Caixin reported on its verified microblog.

"Some interviewees said that they could feel the power of the blast wave even 100 metres away and that the ground was shaking."

Pictures posted on China's hugely popular weibo social networks showed vehicle doors peppered with small impacts, and tyres with holes punched through them.

Other photos showed car windows blown out and debris scattered across the road. One showed two metal spheres the size of large marbles that appeared to have been among the ball bearings sprayed by the bombs.

Images showed several fire engines on a road which had been blocked to traffic, and a large crowd on one side of the street.

Caixin cited sources with knowledge of the matter as saying that "major leaders of Shanxi, including those in charge of petition work and public security, are holding an emergency meeting".

Authorities in China maintain tight control over public security and place huge importance on maintaining social order.

While protests happen regularly, incidents of targeted violence are normally rare.

But on Monday last week a car barrelled into Beijing's Tiananmen Square, killing two tourists and injuring dozens. The three people inside also died after they set the vehicle on fire.

Authorities termed that incident "terrorism" and have said that it was carried out by several people from China's far-western Xinjiang region, home to the mostly Muslim Uighur minority.

China's top security official said a separatist group known as the East Turkestan Islamic Movement was a behind-the-scenes supporter of the attack.

The Taiyuan explosions also come ahead of a highly anticipated meeting of top party leaders in Beijing this weekend, at which broad economic reforms are expected to be on the agenda.

Following the Tiananmen attack, authorities moved quickly to clamp down on discussion of the incident, deleting photos and comments posted on social networks.

But the Chinese Internet was abuzz with dispatches and photos of the Taiyuan explosions on Wednesday, and "Shanxi provincial commission" was the sixth-most-popular search term on the Twitter-like Sina Weibo site Wednesday afternoon.

Timeline of Chinese bombings and other incidents
Beijing (AFP) Nov 06, 2013 - At least one person died on Wednesday when a series of bombs exploded outside a provincial headquarters of China's ruling Communist Party in Shanxi province.

China has seen a number of attacks in recent years, sometimes carried out by citizens disgruntled with their treatment by the government.

Here is a chronology of incidents in recent years:

2008

July -- A man sets off explosions on two buses at Kunming, in Yunnan in the southwest, killing two and injuring 14. He blows himself up in a cafe five months later.

2009

June -- An unemployed man in Chengdu, capital of Sichuan province in the southwest, sets a bus on fire, killing 28 including himself and injuring more than 70.

2010

July -- A man described as an unsuccessful businessman sets an airport shuttle bus on fire in Changsha, capital of the central province of Hunan, killing two people and injuring more than 10. He is later executed.

2011

May -- A man kills three people including himself when he sets off explosions outside three government offices at Fuzhou, in the central province of Jiangxi. He left a note saying he sought revenge after local authorities demolished two of his homes.

June -- A resident of the northern port of Tianjin sets off an explosion near a local government building, slightly injuring two people.

2013

June -- An arsonist kills 47 people including himself on a bus in Xiamen in the eastern province of Fujian, to "vent personal grievances", according to authorities.

July -- A disabled man sets off an explosion at Beijing's international airport, reportedly in protest after he was savagely beaten by police. He injures himself and is sentenced to six years in jail.

October -- A car ploughs into crowds on Tiananmen Square, killing two tourists, crashes near a large portrait of Mao Zedong and bursts into flames, with the three people inside dying. Beijing describes it as "terrorism" and blames separatists from Xinjiang, the far-western province home to the mostly Muslim Uighur minority.