The blaze broke out in the kitchen located at the ground floor of the Regent Plaza hotel at the city's Shahrah-i- Faisal and spread across the six-floor building, trapping nearly 100 hotel guests in their rooms.
Three fire tenders of the fire brigade reached the site and started an operation to rescue the guests. The firefighters were able to contain the fire after three hours, with 11 people having been killed, said Faisal Edhi of the Edhi Foundation.
Mayor of Karachi Waseem Akhtar visited the site of the incident and while talking to media, he said the fire has been contained but the cause of the fire could not be determined as of yet.
He said rescue work was hampered due to absence of an emergency exit and spread of heavy smoke. At least 65 people affected by the fire were brought to the emergency department, Dr Seemin Jamali, head of the emergency services at the Jinnah Postgraduate Medical Centre was quoted as saying by Dawn.
Amongst those were people who had fractured bones after jumping from hotel windows to escape, others had been hurt by shattered glass and many were treated for smoke inhalation, she said.
She said 10 bodies had been brought into the hospital. Six men including four women are among killed. Three foreigners affected by the fire are in a stable condition, said Jamali.
The rescue operation has not ended, and some people are still reportedly trapped inside the hotel. The cause of fire is yet to be ascertained. Pakistan cricketer Sohaib Maqsood was present in the hotel at the time of the incident.
Another cricketer Yasin Murtaza jumped from the second floor to the ground and fractured his ankle. Karamat Ali was injured by broken glass, according to sources.