DUBAI?A cargo plane owned by US courier United Parcel Service caught fire shortly after take-off and crashed in a military base outside the Gulf emirate of Dubai, killing both crew members, civil aviation authorities said.

"The pilot and co-pilot were found dead" in the debris of the Boeing 747-400 at the scene at the crash, the official UAE news agency WAM quoted a brief civil aviation statement as saying.

A statement by UPS, the world's largest courier service, said the plane was flying with a crew of two.

The civil aviation statement did not elaborate on the cause of the crash, but said "measures were taken to contain the fire which broke out on board."

Dubai's state television said that "technical problems" had caused the crash.

Earlier reports had indicated the plane had crashed in an unpopulated area, but an Agence France-Presse journalist said it had come down inside a military base near Dubai's Emirates Road.

Smoke could be seen rising from inside the base, with only ambulances allowed to enter, he said.

An Emirati official told AFP that the accident "has not affected air traffic in Dubai or road transport."

The aircraft had taken off with two crew members from Dubai for Cologne, Germany, UPS said in a statement on its website.

"This incident is very unfortunate and we will do everything to find the cause," the statement quoted Bob Lekites, UPS' international operations manager, as saying.

Witnesses also reported seeing the plane on fire before it crashed.

In October 2009 a Sudanese Boeing 707 cargo plane owned by Azza Transport in Khartoum crashed outside Dubai, near the emirate of Sharjah, killing all six Sudanese crew members aboard.

Sharjah, the third largest emirate after Dubai and Abu Dhabi, is especially used by low-cost airlines and air cargo carriers.