The untiring efforts of rescue teams engaged in finding survivors beneath the collapsed blanket manufacturing factory in this Punjab city saw more success early on Thursday with a trapped worker being rescued after 72 hours under the debris.

Nitish Kumar, a migrant worker from Bihar, walked out to claps around 1 a.m. on Thursday, surprising even his brother and other friends waiting outside the collapsed structure of Shital Fibres here.

As Nitish was taken away by the rescue teams and paramedics to hospital for treatment, his brother, Mithilesh Kumar, said they had lost all hope of seeing him again.

"We are so happy to see him alive. We had almost given up all hopes," Mithilesh said as tears rolled down his eyes.

The four-storey factory building had collapsed late on Sunday and rescue teams of the National Disaster Response Force (NDRF), Punjab Police, other agencies and private volunteers, have been working non-stop since then.

"Our teams were able to create a small tunnel to reach him (Nitish) and get him out. We are trying our best to find any survivors," Col. Simmarjit Singh, leader of the army team, said.

But hopes of finding more survivors under the debris were fast receding even though a teenaged boy was pulled out of the debris early on Wednesday after being buried for almost 55 hours.

Sanjeev Kumar, 17, a worker in the factory, was pulled out by rescue teams early on Wednesday. Rescuers said the youth had no major injuries despite being trapped under heaps of concrete and iron since Sunday midnight.

Rescue teams said they were not able to hear any more sounds of help from under the debris of the factory in Focal Point area in Jalandhar, about 150 km from Chandigarh. Sixty-one people have been rescued so far.

Many more people could still be trapped, officials said as rescue efforts continued for the third day.

According to the authorities, the death toll could rise with many more still under the debris of the Shital Fibres factory, which manufactures mink blankets.

"Our rescue work will go on for two to three days more. We are trying to get near the centre of the pile of the debris to look for any survivors. Our teams are trying to create tunnels from all sides," J.K. Rawat, deputy inspector general (DIG) of NDRF who is supervising the rescue, said at the site.

He said because the debris 'is in a collapsible state we cannot use heavy machinery. We are using technology to find any survivors'.

The owner of the unit, Jalandhar-based industrialist Shital Vij, was arrested on Monday night and booked for culpable homicide not amounting to murder.

On Monday, Deputy Commissioner Priyank Bharti said neither the administration, nor the factory owners had a clear idea of how many workers, mostly migrants from other states, were still trapped under the flattened building.

The safety certification of the collapsed factory had expired over a year ago and had not been renewed. The factory building was constructed four-five years ago.

Shital Fibres claims to be the largest mink blanket manufacturer in South Asia. It is a 100 per cent export oriented unit, exporting mink blankets to several countries in Europe, Middle East, Africa, United States, South America, Australia and Southeast Asia.

The factory has a staff strength of nearly 2,000.