A cargo aircraft en route from Sharjah to Karachi has gone missing approximately 300 nautical miles off the coast of Karachi after losing contact with air traffic control, aviation authorities said on Tuesday night.

According to aviation sources, communication with the cargo flight was lost at around 9.30pm while the aircraft was flying over the Arabian Sea near Ormara.

The Pakistan Airports Authority (PAA) said a search operation has been launched to locate the aircraft, which was carrying five crew members.

The Boeing 737-400 cargo aircraft belonged to K2 Airways.

Preliminary information indicates the Boeing 737 suffered a failure in its navigation system.

The Karachi Area Control Centre (ACC) immediately issued instructions to the crew after the malfunction was detected.

Authorities said the aircraft rapidly lost altitude at 9.21pm before disappearing from radars within seconds.

The missing aircraft belonged to K2 Airways, according to aviation authorities.

As part of the ongoing operation, the Pakistan Navy has dispatched its warship PNS Zulfiqar to the affected area.

A Pakistan Air Force SAAB aircraft is also participating in the search mission, sources added.

The Pakistan Navy’s ATR aircraft has taken off from Turbat and joined the search-and-rescue operation.

Meanwhile, the Pakistan National Shipping Corporation (PNSC) has deployed its merchant vessel Lahore to assist in the ongoing search and rescue efforts, sources added.

In a statement on Wednesday, K2 Airways identified the five crew members on board the aircraft, and said it was “fully cooperating with the Pakistan Civil Aviation Authority and other government agencies”.

“We continue to pray, earnestly, for the safety of our colleagues,” the statement said.

According to preliminary data from Flightradar24, a flight-tracking platform, the plane recorded a sharp fluctuation in altitude before a steep descent.