The UN commission known as CICIG will allow international investigators to work alongside Guatemala’s public prosecutors.

Last month a congressional panel rejected the plan on the grounds that it would violate the nation’s sovereignty. The party of former dictator Efrain Rios Montt from the Guatemalan Republican Front, or the FRG, led the campaign against it.

After the committee’s ruling, the United States and Spain pressured Guatemala to approve the commission, which they said could help stamp out criminals’ influence in the government.

“This is a historic decision for the country, something we have been working on for four years,” said left-wing Congresswoman Nineth Montenegro.

The Central American country emerged from a 36-year civil war in 1996 and is now blighted by violent crime, powerful mafias and corruption, much of it perpetrated by illegal armed groups.

Some of those gangs are made up of former members of the security forces, rights groups say.

A few months ago, the interior minister resigned when drug gang gunmen walked into a prison and killed several jailed police chiefs, themselves accused of murdering a group of Salvadoran politicians.

“Congress concluded that without the international support that the CICIG would provide to the police and public prosecutors, we were on our way to becoming a failed state,” Montenegro said.

Guatemala is a major trafficking corridor for the bulk of cocaine moving from Colombia to the US.

Guatemala approves UN anti-mafia plan – Web posted at: 8/3/2007 – 7:38:46 – Source REUTERS – http://www.thepeninsulaqatar.com/Display_news.asp?section=World_News&subsection=Americas&month=August2007&file=World_News2007080373846.xml

The four men had been detained over suspected involvement in the killing of three visiting Salvadorean politicians.

The officers were shot by armed men who penetrated a maximum security facility, sparking a 12-hour riot among inmates.

Authorities have now arrested the prison’s director and 21 employees, including prison guards.

Investigators are trying to determine how armed men managed to enter the prison and kill the four policemen.

Witnesses said they had seen armed men entering the prison after visitors were forced to leave by the guards, the Associated Press reported.

The policemen were gunned down on Sunday inside the Boqueron prison in Cuilapa, some 40 miles (70km) east of Guatemala City.

The four men killed included the head of the country’s organised crime unit, Luis Arturo Herrera, and three of his colleagues.

The Guatemalan president said the murders of the four men had robbed prosecutors of key evidence about who had carried out the politicians’ killing.