Police in Peru say a 12-year-old girl was killed by the blast of a dynamite stick thrown into her first-floor bedroom in a poor Lima neighborhood.

The death of Yessenia Villa after the attack early Wednesday was the second in a little over a week from explosives in Peru's capital. Villa's father, a security guard, told reporters he had no trouble with anyone and couldn't explain the attack.

A spate of grenade and dynamite attacks has recently plagued several Peruvian cities. Police blame many on extortionists carrying through with threats for nonpayment.

On Sept. 7, a police bomb squad member in Lima died when a grenade he was trying to disarm exploded outside a school at midday.

Authorities say a hand grenade can be purchased in Peru for about $30.