Uighurs are fighting for independence in the northwest

It is not known whether Saturday's explosion has any connection with Friday's blasts.

The head of McDonald's in Xian, Wang Xinwu, told the Associated Press news agency he did not know if the store had been deliberately targeted.

He said they had not received a warning before the explosion.

Xian is home to a sizeable ethnic Uighur Muslim population and Uighur separatists have staged several bombings in western China in the past.

Bombings increasing

Police said Friday's attacks were the work of a local businessman who had targeted his in-laws and others with whom he had economic and debt disputes.

Twenty of the explosions were in Zhanjiang city, where the suspect Lin Guojian lived, the official Xinhua news agency quoted police as saying.

Lin blew himself up, police said.

The other three explosions were in nearby Jiangmen city where Lin was born.

Reports said Lin had taught himself how to make bombs and he used a mobile phone and electronic devices to detonate some of them.

Hong Kong media also reported explosions in the nearby cities of Maoming and Yangjiang, but police and city officials in Maoming said they had no reports of this.

Bombings are on the rise in China, where explosives are cheap and easy to buy.

In March, blasts at a dormitory in the northern industrial city of Shijiazhuang that killed more than 100 people were blamed on a man driven by jealousy and a desire for revenge.