The accused -- Saleem, Munfed, Aamir and Arif -- all residents of Ghaziabad, were arrested from Ravali village late last night, a police officer said, adding three country-made pistols, two live cartridges and Rs 4,500 in cash were seized from them.
"Acting on a tip-off, we laid a trap and arrested the accused," the officer said.
Four of their accomplices, however, are still absconding.
"The arrested have confessed to the crime and we would arrest the rest soon," the officer said.
They also assaulted two employees of the petrol pump when they resisted their attempt.