Men and children cool off during intense hot weather at China Creek in Karachi, Pakistan, June 22, 2015. [Photo/Agencies]

ISLAMABAD - Death toll from the heat waves in Pakistan's southern parts has reached 474, state television reported early Tuesday.

Nearly 300 have died in four major hospitals in the port city of Karachi, the provincial capital, a senior health official, Saeed Mangnejo, told the media.

Meteorological officials say the temperature in Karachi reaches 45 degrees which is a record since 1979.

Head of the Karachi's main state-run Jinnah Hospital, Dr Semi Jamal, said 200 people died in her hospital. She said a vast majority of those dead were above 50 years of age.

She said over 3,000 affected people were brought to hospital over the past three days. Around 200 were stated to be in critical condition.

On Monday, scattered rains had to some extent decreased the temperature.

Prime Minister Nawaz Sharif has expressed deep grief and sorrow over the deaths caused by severe heat in Karachi, the PM office has said.