A 12-year-old and a 15-year-old have been arrested in separate robberies last week on Capitol Hill and in Northeast Washington, D.C. police said Sunday.

The Capitol Hill robbery occurred about 9:30 a.m. Tuesday in the 1500 block of Independence Avenue SE. Police said a 15-year-old boy was charged with snatching a phone from a person's hand.

Also Tuesday, police said, a 12-year-old boy was charged with armed robbery after a person was held up with a knife in the 5500 block of South Dakota Avenue NE.

Police said the attack occurred shortly before 6 p.m. The boy asked for money, police said in a statement, and after the person refused, "the suspect brandished a knife and repeated the demand."

The victim handed over money, and the suspect allegedly ran away. Police said the suspects were arrested shortly after the robberies.