Austin: Emergency officials in Austin, Texas, were grappling with the mistery of another exploding parcel on Monday, the third such incident in two weeks - and the second of the day.

On March 2, a 39-year-old man in north-east Austin was killed after a package on his front porch exploded, police said.

Early on Monday, police responded to a similar package explosion at a home on the east side of the city.

Upon arrival, police found two injured victims inside the home: One, a 17-year-old male, later died, while the other, an adult female, was taken to the hospital with injuries. Police said that incident was being investigated as a homicide.

Then, shortly before noon, local time, police responded to a third explosion, this time on the south-east side of the city.