US passenger 'tried to open door' mid-flight to Houston

A plane travelling from Los Angeles to Houston was diverted after a woman tried to open an emergency exit near the end of the flight, passengers say.

The woman, who police have not named, was subdued by a police officer who had joined the force two weeks earlier.

A passenger on Southwest Airlines Flight 4519 told KHOU-TV that the woman was behaving erratically throughout Sunday's morning flight.

"She wrote 'Help me' and her name" on napkins, the traveller said.