BEIJING — Chinese authorities were investigating two explosions Friday in a basement car park and a 30th floor apartment in the country's northeast that left one person dead and one injured.

Police in the city of Changchun said in a microblog message that the blasts in the Wanda complex were being investigated as criminal acts.

Few details were given other than that the apartment explosion occurred at 3:16 p.m.

Calls to the building's management office rang unanswered Friday evening.

Wanda is a global real estate, film production and sports management conglomerate that has built shopping malls and housing complexes across the country.

China is on a security alert ahead of next month's Lunar New Year holiday, when tens of millions of people travel by rail, road and air to see relatives.

With tight controls over firearms, most personal attacks in China are carried out using knives, axes or homemade explosives.