In Hai Phong, gun shots can be heard on the streets in broad daylight.
Young men in the northern port city do not hesitate to draw their guns for the most minor of conflicts such as disputes over online games or cards.
One such incident happened on May 14.
At around 1 p.m., people going about their business on Lach Tray Street in Ngo Quyen District rushed out of the way of two oncoming motorbikes carrying eight men who were being pursued by two gunmen, namely Nguyen Manh Duy, 21, and Thai Anh Tung, on another motorbike.
When the pursuers were within range, they fired and one of the eight fell. His group refused help from locals while the gunmen drove away after being chased by police. The gunmen escaped.
Duy, afraid of facing more severe charges if he did not own up to what he had done, went to the police the day after. His accomplice Tung is still at large, the police said.
The police also named some members from the other gang, four of whom are 18 years old. Further investigations into the cause of the shooting were underway, they added.
A Hai Phong police officer, who did not want to be named, said the cases were "serious" as the men were violent and had no consideration for others
The aftermath of a shooting between two illegal mining groups in the northern Quang Ninh in December 2008, in which six members from one group were killed. Guns have joined in more conflicts between northern gangsters, police said.
A senior investigator from Hai Phong police, who also asked to remain anonymous, said "never before have gangsters dealt with each other in such a cruel manner."
On the evening of April 23, ex-con Nguyen Cong Tu, 22, was shot dead on Tran Nguyen Han Street after his group and another argued over card games.
Five other members of the gangs range between the ages of 26 and 33.
Most of the gangsters have left home and have been on the streets for a long time, so it is hard to keep track of them, said police.
Controlling gun crime in Hai Phong is a difficult task, especially now that gangsters equip themselves with pen-shaped guns that are easy to hide and very effective.
This specific model was first smuggled from China and used for several murders in 2008. But, earlier this year, local Vo Tien Dat, 24 managed to reproduce the gun himself, before being caught last week.
In the nearby Quang Ninh Province, gangsters also shot at police.
Last month, a traffic police officer was shot in the stomach when he stopped Nguyen Thanh Long, 23, and Vu Trong Hai, 20, for driving recklessly. The officer was off duty.
One of the most savage gang shootings in Quang Ninh happened in December 2008, when six people were killed, including three 13-year-olds.
The shootout occurred between two illegal mining groups, one of which wanted to claim dominance over coal mines around the northeast of the province.
Quang Ninh police said other shootings took place due to minor conflicts like when one man did not like the way others looked at him.
Some gangs have been around for a long time and have earned a reputation in the underworld.
Some only come together when one member has a problem or needs help.
"Gangsters these days, especially teenage ones, are cold blooded and intensely loyal to one another. If one member of their group needs help, they will do anything and everything to help," said a senior investigator from Quang Ninh.
"Many gangsters use synthetic heroin. The drug lessens their brain functions and makes them more violent. They are willing to use guns to kill anyone like cold blooded murderers," the official said.
Nationwide statistics showed that gangsters used guns and other military weapons in 28 cases during the first three months of this year.
Last year, guns were involved in 79 more conflicts than in 2008, figures showed.