Violent crime in the Caribbean nation has soared over the past decade as drug trafficking has increased.

Official statistics show 10% of homicides in 2010 were carried out by the police.

Most fatal shootings were described by police as the result of exchanges of gunfire with criminals.

But in many cases, Amnesty says forensic evidence supports allegations that police "deliberately shot to kill" to deter crime.

The police have stressed that the high number of killings is partly the result of their determination to confront rising levels of violent crime and drug-trafficking.

They also point out that many officers have been killed, and say unlawful killings by police are isolated cases.

But Amnesty says the problem is much wore widespread than the authorities admit, and is contributing to the rise of violent crime.

"We acknowledge that police officers usually face dangers while doing their jobs," said Javier Zuniga, the head of Amnesty's delegation to the Dominican Republic.

"However, we believe their conduct is actually exacerbating the violence and creating a climate in which human rights are completely ignored."

Amnesty adds that the police are widely seen as "authoritarian, corrupt and ineffective," with extortion and collusion with criminals believed to be common.

The Dominican government has acknowledged that there are high levels of corruption in the police, and thousands of officers have been dismissed from the force in recent years.

Amnesty is urging reform to the police and justice system so that killings and human rights abuses by police are properly investigated.

It says prosecutors must be given more independence, forensic services must be improved and witnesses must be given greater protection.

It further urges the Dominican state to accept responsibility for human rights abuses committed by police and recognise the extent of the problem.