A police officer who requested anonymity because he was not authorized to speak on the matter said the pop star was being taken to "get help" but did not say where she was headed.

It was the second time this month that Spears, 26, was taken from her house by ambulance.

On Jan. 3, police were called to her Studio City home when she refused to return her two young sons to ex-husband Kevin Federline, who has legal custody.

Officers at the time had paramedics haul Spears to a hospital for undisclosed reasons. She was released after a day and a half in Cedars-Sinai Medical Center.

Police on motorcycle sand in unmarked cruisers were at the house Thursday when she was taken away, according to celebrity news Web sites.

Spears recently lost visitation rights with her sons, Sean Preston, 2, and Jayden James, 1. She and Federline divorced in July after nearly three year of marriage.

The bitter custody dispute and several episodes of bizarre behavior by the singer have attracted scores of paparazzi, who stake out her house and tail her when she leaves.