Seven teenagers aged 14 to 19 have been arrested in two stolen-car incidents, including three who allegedly fled into the National Museum of Australia after crashing into a taxi.

Police spotted a stolen Mercedes SUV being driven erratically in Lyneham about 10am on Tuesday and followed it until it collided with a taxi outside the museum.

Three occupants fled into the museum, with a 15-year-old girl arrested outside and a 17-year-old boy and 19-year-old man arrested inside.

All three faced court on Tuesday charged with various theft and stolen vehicle offences.

About two hours later, police received reports of a stolen Kia Rio being driven erratically near Melba High School. Officers followed the car to Flynn, where four boys aged between 14 and 17 were arrested.

Two have been charged with stolen vehicle offences, while the other two were released and may be charged later.

Five of the seven teenagers were known to police, with the 19-year-old and one of the 17-year-olds subject to good behaviour obligations.

Anyone with information or dash-cam footage of either vehicle is urged to contact police via the Crime Stoppers ACT website.

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