Two suspected bank robbers, one of them wearing a St Patrick's Day costume, have been killed in a shootout with police in Tennessee.

First State Bank in the Nashville suburb of Gallatin was held up on Wednesday by a man dressed as a leprechaun, police said.

The man left the bank with an undisclosed amount of money.

Both suspects were shot dead when they ditched their vehicle and ran into a field, pursued by police officers.

The costumed suspect had initially walked into a Fifth Third Bank nearby at lunchtime but left again because it was too crowded, witness Bradley Webb told Tennessee's News Channel 5.

'Large-calibre gun'

Sharon Riehemann, manager of the Fifth Third Bank, said the costumed man had been wearing a green top hat, vest and shorts and a fake brown beard and wig.

"He started to come in, then looked at his watch, then turned around and left," she was quoted as saying by the Associated Press news agency.

After holding up First State Bank with a large-calibre gun, police said, the "leprechaun" man joined another suspect waiting in a car outside.

Police spotted the car with the two suspects fleeing the scene and a car chase ensued.

One police car was hit by several bullets and the car broke down as a result, Sgt Bill Storment of the Gallatin Police Department was quoted as saying by Channel 5.

The suspects left their car in a field and fled on foot. They were killed while exchanging fire with officers, police said. No officers were injured and money was recovered from the suspects' vehicle.

Both suspects were pronounced dead on the scene.

The leprechaun, a solitary elf in Irish fairytales, figures in celebrations to mark St Patrick's Day.

AP notes that the case is reminiscent of a 22 December robbery in Nashville when a man dressed in a Santa suit - including hat, beard and moustache - held up a SunTrust Bank, demanding money from the teller at gunpoint. No arrests were made in that case.