Witnesses to the December double slaying at an Avondale bonfire described a terrifying scene as about a dozen weapon-wielding Surenos encircled two members of the rival Viking gang, police said.

Details about the Dec. 3 party in New Garden Township that turned fatal for  Cuahuctemoc Bedolla, 27, and Jose Rodriguez, 29, both of West Grove, emerged today after police filed criminal complaints for 10 new defendants. Nine were taken into custody during a predawn sweep. One was already in prison on unrelated charges, and two were charged several days after the homicides.

According to the criminal complaints, witnesses - who were not identified for their protection - said a group of Surenos, also known as Sur 13s or Southsiders, were asked to leave an outdoor party because members of the rival Viking gang were present. One of the party's organizers made the request, "knowing that they always fight." Although the Sur 13s left, they began assembling a larger group to return and attack the Vikings, the complaint said.

Witnesses said two groups of Surenos, brandishing knives, bats, pipes, boards, brass knuckles, and broken bottles, approached the two Vikings from two directions, quickly surrounding them. The Surenos, many of whom had blue bandanas wrapped around their hands, launched a quick, deadly assault, the complaint said.

Bedolla was stabbed so violently that one stab wound penetrated an inch into a spinal bone, causing the knife to get stuck. Rodriguez also had multiple stab wounds, one that penetrated five inches into his torso and another that severed his right kidney, the complaint said.

For more information on today's news conference announcing the arrests and the dozen defendants in custody, see http://www.philly.com/philly/news/breaking/20120130_10_more_arrested_in_Chesco_gang_related_killings.html