BEIJING (AP) — An explosion has occurred in the parking lot of an airport in China’s northwest but there was no immediate word of any injuries.

The newspaper China Youth Daily said the explosion occurred at 1.45pm in a trash bin in a parking structure at the airport in Xining, capital of Qinghai province. It said police sealed off the area.

A woman who answered the phone at Xining police headquarters confirmed an explosion occurred but refused to say whether there were any injuries.

Chinese authorities have stepped up security in airports and train stations following a series of violent attacks blamed on Muslim extremists.

Photos on the China Youth Daily website showed police at the airport but no signs of damage.