(DPA)

Pakistan's Prime Minister Shehbaz Sharif has confirmed that a cargo aircraft operated by the Pakistani airline K2 Airways, with five crew members on board, has crashed into the Arabian Sea.

In a statement issued on Wednesday, he extended his condolences to the families of the crew. 

Sharif expressed his dismay over the incident and said he had instructed the military and emergency personnel to intensify search and rescue efforts.

The K2 Airways Boeing 737 was en route from when it disappeared roughly 300 kilometres west of Karachi, Pakistan’s Civil Aviation Authority said in a statement.

The aircraft experienced a sharp loss of altitude before regaining height and then descending again at around 9:30pm local time on Tuesday, the authority said.

Shortly before that, the crew had reported navigation problems, it added.

Military aircraft and navy rescue boats were taking part in the search, but had not yet located the missing plane by Wednesday morning, an official told DPA. 

Those on board included a pilot, co-pilot, two engineers and a loadmaster. The Boeing 737 had been in service since 1999, initially as a passenger aircraft before later being converted for cargo operations.

K2 Airways is a Pakistani cargo airline that began operations in 2018.