Media playback is unsupported on your device Media caption Recent attacks have provoked discussion about social and economic inequality, the BBC's Lucy Williamson reports

A series of small blasts have killed at least one person outside a provincial office of the ruling Communist Party in northern China, state media report.

The blasts in Taiyuan in Shanxi province appeared to have been caused by home-made bombs, Xinhua reported.

It said eight people had been injured and two cars damaged.

Photos posted on social media showed smoke and several fire engines at the scene of the incident, which happened around 07:40 local time (23:40 GMT).

No immediate explanation has been given for the incident. There have been occasions in the past where disgruntled citizens have targeted local government institutions.

Analysis They do not often make the headlines but explosions in China's cities are not unheard of. Earlier this year, in another part of Shanxi Province, Chinese media reported that a bomb exploded outside the house of a local law official, killing his daughter. The culprit was a pensioner enraged by a court ruling against him. Last year the BBC reported on a suicide bombing in Shandong, carried out by a disabled man upset by lack of compensation for an industrial accident. Every year there are examples of attacks with crude weapons or explosives, carried out by the desperate, the dispossessed and the disturbed, usually triggered by a dispute with some arm of local government or a local official. It's too early to say whether the explosions on Wednesday follow the same pattern. But some details will worry the authorities: the ball bearings apparently placed inside the bombs, increasing their destructive power; the fact that witnesses reported several explosions over a period of time. And the bombs were placed outside the local Communist Party headquarters - was the party itself the target, or was this just the product of a local dispute? The authorities will especially be nervous after last week's apparent suicide attack outside the gates of the Forbidden City, especially as the capital also prepares to host a meeting of China's Communist Party elite on Saturday.

Tensions are also high in the wake of last week's incident in Beijing. A car ploughed into a crowd in Tiananmen Square in what the authorities said was a terrorist attack incited by extremists from the western region of Xinjiang.

Later this week, the Communist Party's top officials will meet in Beijing to start a major economic planning meeting.

'Seven loud blasts'

"Several small explosive devices went off at Taiyuan's Yingze Street near the provincial party office," Shanxi police said in a post on their verified microblog.

"Provincial leaders went to the scene immediately, and police are currently investigating the case," the post added.

"Police officers found steel balls, circuit boards and similar explosive materials at the scene," state-run news agency Xinhua said.

"The initial judgement is that the explosions were man-made."

The explosive devices were hidden in roadside flower beds, according to Chinese state television.

However, two witnesses told Xinhua they saw a minivan exploding, sending car debris flying.

Eyewitnesses also told Xinhua they heard "seven loud blasts", and saw a large amount of smoke at the site.

Image caption This image circulating on social media appeared to show ball bearings used in the home-made devices

Image caption Car windows were shattered at the site of the blasts

Image caption Police cordoned off the street as they investigated the case

Image caption Residents gathered in the streets following the explosions

Photos posted on microblog Sina Weibo appeared to show cars windows and tyres that were damaged as a result of the blasts, as well as metal ball bearings.

One of those injured was in a serious condition, state media said.

Taiyuan police said in a verified microblog post that two-way traffic was restored on Yingze Street at 10:30 local time (02:30 GMT).

Taiyuan, the capital of Shanxi, a province in north central China home to large-scale coal mining, is home to more than four million people.

'Furious ways'

The blasts quickly became one of the most discussed topics on Chinese microblogs.

On Sina Weibo, one of China's largest microblog providers, the term "Shanxi provincial commission" was the second-most used search term on the site, while "Taiyuan explosion" came sixth.

Many users expressed shock at the use of ball bearings in the bombs. "This is too ruthless," user Lawyer Wang Junsun wrote.

User Hemlocks wrote: "In these days it is the best not to wander about at places with political symbolism. If one has to go, then one should be extra careful."

Several users linked the incident to growing social and economic pressures in the country.

Microblog user Xurizhaohaifeng said: "This proves that high-handed policies do not bring stability, it will only explode in other more furious ways."

User Haoling A wrote: "We are against all acts of terrorism! But we are also opposed to [the government] using the excuse of anti-terrorism to turn China into a country ruled by the police!"