PORT MORESBY, Papua New Guinea -- Five men were shot dead in a gun battle with police in Port Moresby today after hijacking a helicopter and landing it on the roof of a bank in a raid in the heart of the Papua New Guinea capital, police said.

The men, armed with rifles, pistols and hand grenades and all dressed in army uniforms, landed on the PNG Banking Corp. building around 11 a.m. and made their way into the bank.Once inside the bank, they fired several shots into the walls.

But police had been tipped off, and undercover police officers inside the bank returned fire, forcing the gunmen to retreat to their helicopter on the roof.

"The criminals then tried to escape in the chopper, but a large police presence outside the bank premises shot the craft as it was ascending, causing it to crash on the road," Police Chief Superintendent Raphael Huafolo said in a statement.

"The criminals scrambled out of the wreckage and tried to attack a massive police pack. All five suspects involved in the robbery incident were killed in the gun battle with police."

The pilot, who had been hijacked from nearby Port Moresby airport, managed to flee the wreckage unharmed.

During the gun battle in downtown Port Moresby, shoppers and office workers fled in fear. Fire trucks had been parked near the bank out of concern the bank robbers would use explosives.

Despite their army uniforms and arms, police said the five men were well-known criminals. One had been wanted for shooting at a police helicopter several weeks ago.

Crime is endemic in Port Moresby, where criminal gangs known as "Raskols" operate freely. Homes, hotels and diplomatic missions are all surrounded by razor wire and gun battles between police and criminals are not uncommon.