ISLAMABAD -- Two people were killed and 85 others injured in separate incidents of firing by residents of Pakistan's southern port city of Karachi to celebrate the country's 77th Independence Day on Monday, police and hospital administration said.

The killed included a man and woman who received stray bullets which were fired in the air by unknown residents as a part of the celebration, the Karachi police told media.

The woman was traveling on a motorbike when she got hit by the bullet whereas the man was sleeping on the roof of his home when the stray bullet struck him, the police said.

The injured people are being treated at three major hospitals in the city, and some of them who got bullet injuries in the head are in critical condition.

The Karachi police imposed a ban on firing bullets in the air commonly known as aerial firing in the city, warning the public of consequences if the order is not followed.

Talking to the media a day ahead of Independence Day, Syed Husnain Haider, deputy superintendent police of Karachi, said that a special squad had been formed to prevent one-wheeling, display of weapons and aerial firing, adding that law violators would be treated with iron hands.

An investigation into the firing incidents is underway, and the culprits will be brought to bolls soon, the Karachi police told media.