MUNICH (AP) — Police closed the Oktoberfest fairgrounds Wednesday morning following a bomb threat from the suspected perpetrator of an explosion in northern Munich, city officials said.

At least one person's death was believed to be connected to the explosion at a residential building early Wednesday, which Munich police said was deliberately set on fire and part of a domestic dispute.

It was not immediately clear whether the deceased was the suspected perpetrator or someone else. Another person, who was not considered to be a danger to the public, remained missing.

Specialized teams were called to the scene to defuse booby traps in the building, police said.

Officials discovered the bomb threat to Oktoberfest in a letter from alleged perpetrator. Police searched the fairgrounds for other explosive devices and asked workers to leave the area. Authorities said the festival will be closed at least until 5 p.m. local time (1500 GMT) Wednesday.

This year’s Oktoberfest began on Sept. 20 and ends Oct. 5. The world’s largest beer festival usually attracts up to 6 million visitors.