BROOKLYN - Police are looking for a man who assaulted a woman inside the subway in the Bronx.

It happened inside the Livonia Avenue L train subway station on March 4.

Police say the man approached the woman from behind and threatened to kill her if she didn't give up her cellphone.

Police say the woman fought back and there was a brief struggle, but the man punched the woman in the head before running off with her cellphone.

Anyone with information is asked to call the NYPD's Crime Stoppers hotline at 1-800-577-TIPS