CHALLIS, Idaho -

Six more earthquakes have occurred near the central Idaho town of Challis.

The U.S. Geological Survey says the temblors started at about 1 p.m. Monday and ranged from 2.5 to 4.6 in magnitude.

Three of the quakes took place within a 40-minute span starting at about 9:12 p.m. Monday.

The quakes ranged from 6 to 15 miles northwest of Challis in lightly populated Custer County.

The quakes near Challis follow a 4.9-magnitude shaking on Sunday and a 4.1-magnitude quake on Thursday.