BEIJING (AP) — A series of small explosions killed one person and injured eight others Wednesday outside the provincial headquarters of the ruling Communist Party in the northern Chinese city of Taiyuan, officials said.

Officials gave no word on the target or perpetrators of the blasts, which state media said were caused by homemade bombs.

The explosions came during heightened security following a suicide car crash at Tiananmen Gate in Beijing that killed the car’s three occupants and two bystanders in what officials called an act of terrorism committed by Muslim militants from western China.

However, Wednesday’s blasts also were reminiscent of the kind of revenge attacks occasionally launched by disgruntled citizens in China. Assailants angered at perceived injustices have blown up buses, stabbed officials and attacked schools.

The Shanxi provincial government and police said the blasts occurred at about 7:40 a.m. The official Xinhua News Agency cited unidentified police sources as describing the explosives as improvised bombs, although police spokesmen declined to confirm that information.

One of the injured was listed in serious condition, and a bus and several other vehicles had their windows blown out or suffered other damage.

A street cleaner interviewed on state television said the explosives were planted in flower beds in two separate locations and that eight blasts were heard in all.

Footage showed the blast scene littered with nails and steel balls of various sizes, apparently packed into the bombs to cause maximum damage and injury. Blood stains were visible on the sidewalk and on the door of a damaged SUV.

Xinhua quoted a witness, Liu Guoliang, as saying smoke and flames were seen pouring from a minivan.

Police closed off the broad street in front of the party headquarters, and fire trucks, ambulances and police vehicles were parked in the area. State media showed a man lying on the ground, apparently dead.

Taiyuan is the provincial capital of mountainous Shanxi, which lies to the west of Beijing in China’s gritty coal belt. Demand for the fuel has created vast fortunes for mine owners, but many in the province still live in poverty.