Thirteen bodies have been recovered from a mass grave near Mexico City, five of which are remains of young people kidnapped in the capital in May, officials said.

"The remains of 13 people were recovered," federal prosecutor Renato Sales told reporters on Friday, adding that forensics tests revealed the identities of five of the victims.

Officials said DNA tests would continue to identify the eight other "badly decomposed" bodies.

The grave was discovered on Thursday on a rural ranch in Tlalmanalco, east of the capital.

The five are among 12 young people who were kidnapped from a downtown bar three months ago in a case that has shocked the capital and marred its image as an oasis from drug cartel violence.

There was no immediate explanation about how the 13th body was related to the kidnapped youths.

Officials had earlier reported the discovery of seven bodies on a ranch adjacent to a park 30km southeast of Mexico City.

'Organised crime'

Ricardo Martinez, a lawyer for relatives of the missing, said there is no doubt the other bodies would also be identified as the missing youths, most of whom are from the rough Mexico City neighbourhood of Tepito.

"They're going to wind up identifying all of them,'' Martinez told AP news agency.

"I hope the SEIDO [the federal attorney general's office for organised crime] takes over the case, because now it's proven that this is organised crime."

Prosecutors have said the abductions from the Heaven bar were linked to a dispute between street gangs [AFP]

Investigators found a pistol, a shotgun and several pairs of handcuffs at a home on the ranch where the mass grave was found.

Prosecutors have said the abductions from the Heaven bar, in the popular Zona Rosa entertainment district of Mexico City, were linked to a dispute between street gangs that control local drug sales in the capital's nightclubs and bars. 
They say the gangs are based in the Tepito neighbourhood where most of the missing lived.

Two of the missing youths - whose bodies have still not been identified - are sons of imprisoned drug traffickers, but the families insist the missing young people were not involved in drug trafficking.

Al Jazeera's Adam Raney, reporting from Mexico City, said the kidnapping, which took place in broad daylight, "shook up the city, and angered the public".

"This kidnapping kind of woke people up here as it brought [the violence] home to the capital," he said.

An estimated 70,000 people have died in drug-related violence in Mexico over the past six years.

The violence has mainly been concentrated in the northern states and in the west, with the capital largely spared.

Source: Al Jazeera and agencies