Montgomery County police are asking residents countywide, including those in Bethesda and Chevy Chase, to help locate two missing children: Rosa Angelica Gaitan, 12, and Audy Lopez-Oliva, 15.

The department's Special Victims Investigations Division issued both alerts around 2:45 p.m. Tuesday, Aug. 11, according to the Montgomery County police department. The cases mark the third and fourth missing-child alerts MCPD has issued this month.

Rosa Angelica Gaitan was last seen Monday, Aug. 10, around 4 p.m. on Croydon Court in Silver Spring, according to a county press release. She is 5 feet 4 inches tall, weighs 125 pounds and has shoulder-length hair dyed red and brown.

She was wearing a light-colored or white short-sleeve T-shirt with a small, multicolored Mickey Mouse print and blue-and-white checkered pajama pants with a small bow pattern.

Audy Lopez-Oliva was last seen Tuesday, Aug. 4, between 3 p.m. and 5 p.m. near the 17000 block of Larchmont Terrace in Gaithersburg, according to a separate county press release. Lopez-Oliva is 5 feet 5 inches tall, weighs 140 pounds and has black hair and brown eyes. The teen was wearing a black shirt and blue jeans.

The public alert for Lopez-Oliva came one week after the teen's last known sighting. Police did not explain the gap.

How to help

Anyone with information on either child should call the Montgomery County Police non-emergency line at 301-279-8000.

Anonymous tips can be submitted to Montgomery County Crime Solvers at 1-866-411-TIPS (8477), online at p3tips.com, or through the Crime Solvers mobile app.