Five officers from the ministerial police - the Oaxaca state force that has been at the center of the violence and protests that have reigned over Oaxaca since June - were detained by Federal Preventative Police (PFP), who were backed by Federal Intelligence Agency (AFI) personnel.

Two are suspected of carrying illegal firearms and three of possessing stolen vehicles.

About 40 PGJE employees were searched during the sweep, which began at 4 p.m. Many others fled the building, eyewitnesses report, as the heavily armed PFP and AFI troops roared in from the airport in some two dozen vehicles.

But the aim of the sweep went beyond stolen vehicles and illegal weapons. Ardelio Vargas, a high- ranking PFP official, said in a radio interview that confiscated firearms would be tested for possible connections to shootings that have left anywhere from nine to 19 persons involved in the protests dead since June.

The operation, Vargas said, had been coordinated with the federal Attorney General´s Office (PGR). The PGR released a statement Friday night confirming that the state police guns will be tested as possible murder weapons.

The federal officers occupied the building for more than an hour before retiring. The PGJE is the same building that protesters from the Oaxaca People´s Assembly (APPO) occupied briefly at the height of its protest actions this summer.

PFP troops had moved into Oaxaca in October to dislodge protest encampments throughout the capital city, and then arrested nearly 200 protesters during a Nov. 25 demonstration that descended into violence and vandalism.

The new sweep came just hours after APPO representatives presented Interior Secretariat officials in Mexico City with a letter alleging human rights abuses against the arrested protesters, most of whom are being held outside Oaxaca, in the state of Nayarit.

According to the APPO allegations, the detainees have been subjected to sexual harassment, psychological torture, having their heads forcibly shaved and being held incommunicado.

The Interior Secretariat officials at the meeting, headed by Government Undersecretary Mario Escárcega, accepted the letter but made no comment. APPO and Interior representatives are scheduled to meet again on Tuesday. New Interior Secretary Francisco Ramírez Acuña is expected to attend that meeting.

APPO spokespersons, including Erangelio Mendoza who heads the APPO contingent in the talks, insist the demonstrators and APPO leaders are being held illegally, and are in fact political prisoners.

Authorities and activists don´t agree on how many demonstrators and APPO leaders are currently being held, or on how many deaths have occurred.

But Oaxaca state prosecutor Lizbeth Caña put the number of deaths at seven, with only four connected to APPO. She also said arrests since Oct. 29, the day the PFP moved in, stand at 284, far below the 500 APPO spokesman Florentino López asserts.

Caña, like most Oaxaca state officials a member of the Institutional Revolutionary Party (PRI), is a controversial figure in the Oaxaca crisis. Last month, she suggested that there was evidence linking the murder of U.S. photojournalist Bradley Will to APPO activists, and freed the two municipal police officials who were being held as suspects in the case.

On Friday, local legislators from the PRD and PAN, normally at odds, walked out of the state congressional chamber as Caña was speaking. The two parties claim Caña has been tapping their phones, and they called for her resignation.

The national PRD will join an APPO-organized march Sunday to demand the release of the arrested demonstrators. Both APPO and the PRD want the PRI´s Ulises Ruiz removed from the Oaxaca governorship.

EL UNIVERSAL staff writer Jorge Octavio Ochoa in Oaxaca contributed to this report.