Another blast rocked Liuzhou city yesterday morning, causing bricks from a six-storey building to rain onto the streets below and keeping the city on edge as China celebrated its national day.
Chinese media reports quoted residents as saying the 8am explosion was loud and tremors could be felt from their beds. Pictures showed a crowd gathering at the scene, surveying shattered pieces of bricks on the pedestrian walkway and road.
There were no reports of casualties from the latest blast, which comes a day after at least seven people in the south-western Guangxi region were killed by a series of parcel bombs that went off in hospitals, shopping malls and government offices. Another 51 were injured, with two reported missing.
Singapore's Ministry of Foreign Affairs said in a statement yesterday that no Singaporeans were affected by the blasts, and conveyed condolences to the families of the victims.
Local police also revealed on Wednesday night that they have found more than 60 suspicious packages following tip-offs from residents. They have despatched explosives experts to investigate.
Southern Metropolis Daily reported yesterday that the perpetrator may have detonated the explosives remotely, or paid unsuspecting accomplices to deliver the packages.
Liuzhou's postal services have stepped up safety checks and will suspend postal services till tomorrow. The authorities have also advised locals to avoid suspicious packages placed in public.
"The public must be on guard. Do not accept or pass items on for strangers. Do not accept parcels that arrive from unusual channels," Liuzhou police were quoted as saying on their social media Weibo account.
The authorities have detained a 33-year-old Guangxi man surnamed Wei for carrying out "criminal activity" and ruled out terrorism, but they have not elaborated on his motives or said whether he acted alone.
But US-based intelligence firm Stratfor said in a report that the scope of the attack and damage suggested a coordinated effort and that "suspicion may focus on a militant arm of China's Uighur minority".
"Liucheng is not one of the counties near the Vietnamese border, but the greater Guangxi province and neighbouring Yunnan make up part of a human smuggling route for ethnic Uighurs out of China to... South-east Asia," it said, adding that this may rekindle worries about the rise of Uighur militancy.
Yesterday also marks the 60th anniversary of the founding of Xinjiang in western China, a region that has in recent years been marked by strife between Beijing and the majority Muslim Uighurs.
But analysts told The Straits Times that it is difficult to conclude an Uighur or terror link, given the information available. "As the Unabomber has shown, it's possible for one person to plan many attacks, if he is using couriers," said Lanzhou University counter-terrorism expert Yang Shu, referring to American criminal Ted Kaczynski who mailed homemade bombs to his victims.
They pointed out that one definite concern following the deadly blasts is the safety of courier services in China, which has boomed in recent years as consumers embrace e-commerce. "Courier companies are not enforcing security measures strictly because of the volume of packages," said Renmin University security expert Guo Taisheng. "This needs to change if future incidents are to be prevented."