Itanagar, Nov. 21: Standing on the terrace of the yet-to-be completed new office of the district jail at Jully in the Arunachal Pradesh capital, superintendent of jail Michi Paku points at the male ward from where four inmates escaped on Thursday night.

Serial bank robber Hiba Tajuk, along with Dora Sanjay alias Dora Tadu, Monuj Phukan and Raju Pegu, who were arrested for their involvement in the kidnapping and murder of businessman K.P. Chako, escaped from their cell sometime between 1.30 and 4am, Paku said.

The inmates cut off the window grilles with a hacksaw blade before making their way to the kitchen to make a ladder from firewood, tying them with torn pieces of blankets that were used as ropes. The four then proceeded to the female ward where the watchtower is unmanned and scaled the 18-feet high wall with their makeshift ladder.

In a scenario reminiscent of the June 1962 escape of inmates Clarence and John Anglin, and Frank Morris from Alcatraz in San Francisco, the US, the four laid pillows on their bed and covered them with blankets to give the impression that they were sleeping. By the time the discovery of their escape was made, the four had long disappeared.

Jail authorities have suspended the jail wardens who were on duty that night. They have been arrested under the charges of aiding and abetting the escapees.

Paku said an "internal hand" is suspected without which the escape would not have been possible.

Blaming negligence and carelessness on part of the wardens, Paku said they did not conduct their rounds. In August, an order was issued to ensure that wardens inspect the ward premises, window and door grilles every two hours. The order also said guarding duties must be rotated, noting that inmates have occasionally attempted to scale the prison walls in the past. This latest escape is the second time that such an incident has taken place since the jail became functional in November 2009. In August 2012, three undertrial prisoners had escaped.

Spread over six-and-a-half acres of land, the jail has revamped its infrastructure. However, security infrastructure still requires work. Until the end of last year, the jail had the capacity to hold just 56 inmates (44 males and 12 females), while the actual prison population was 127 (123 males and four females). The jail has since completed a new male ward, which can house an additional 100 inmates. Before the latest escape, there were 117 inmates with room to spare.

However, there are other areas of concern. The jail has been operational for six years but it still does not have a CCTV camera installed anywhere on the premises. Paku said funds for the cameras were released recently and they will be installed before the year is over.

He also said the four escapees scaled the wall on the female ward's side because the watchtower overlooking that section is unmanned "to respect privacy" of the female inmates.

Till March this year, the Jully jail was the lone district jail in the state before a second district jail was made functional at Tezu, the headquarters of Lohit district. There is no central jail in the state.