Teen punches officer in head during arrest

A teenager has been charged with assaulting a police officer following an alleged domestic incident in Blacktown, in Sydney's west.

Officers were called to a home in Shalvey after reports of an assault and arrested a 17-year-old boy at the residence.

Police allege when the teen was placed in the rear of a caged truck, he grabbed hold of a leading senior constable, dragged him into the vehicle and punched him several times in the head.

The teen was subdued before being charged with common assault, assaulting police in execution of their duty, resisting police in execution of their duty and intimidation.

The officer suffered bruising and swelling to his face and head, NSW Police said in a statement.

The 17-year-old has been refused bail to appear in a Children's Court on Friday.