By Dan Whitcomb

LOS ANGELES (Reuters) - Pop star Chris Brown was arrested on suspicion of assault with a deadly weapon on Tuesday after a daylong standoff and search at his Los Angeles home that began when a woman called 911 in the predawn hours, police said.

Brown, 27, denied any wrongdoing in posts on Instagram before he was taken into custody and said he had woken up to find police outside the property in the Tarzana neighborhood in Los Angeles' San Fernando Valley.

"He is being transported to robbery homicide, where he will be arrested for assault with a deadly weapon, Lieutenant Chris Ramirez of the Los Angeles Police Department told reporters at an impromptu media conference outside Brown's home.

Ramirez declined to elaborate on the charges against Brown, saying an investigation was still under way. Earlier and the Los Angeles Times reported that the singer had pointed a gun at the woman, who later left the property.

Police who responded to the 911 emergency call at around 3 a.m. spent hours surrounding the home before obtaining a search warrant and beginning a search of the sprawling premises in the early afternoon.

During that search, TMZ posted a photo of Brown standing on the front porch with a police officer and his attorney, Mark Geragos. Geragos could not be reached by Reuters for comment.

"I don't sleep half the damn night I just wake up to all these ... helicopters, choppers is around, police out there at the gate," Brown said in a video he posted on Instagram as police were stationed outside his house.

"What I do care about is you are defacing my name and my character and integrity," he added, saying he had done nothing wrong and criticizing police actions.

"I don't care y'all going to stay playing with me like I'm the villain out here, like I'm going crazy ... good luck when you get the warrant or whatever you need to do. You're going to walk right up in here and you're going to see nothing you idiots," he added.

In 2009, Brown assaulted his then-girlfriend Rihanna, and in 2015 finished a lengthy term of probation, community service and domestic violence classes.

(Additional reporting by Jill Serjeant; Editing by Bill Rigby and Peter Cooney)