SKOPJE (AFP) - A series of pilot errors caused the plane crash that killed Macedonian president Boris Trajkovski and eight other people in Bosnia in 2004, the results of an international probe showed Saturday.

The outcome confirmed the findings of an initial investigation by Bosnian authorities immediately after the accident.

"Several systematic pilot errors were key to the fall of the plane," said Omer Kulic, head of an international commission that has been conducting the probe for the past two years.

The crash on Feb 26, 2004 occurred when the US-made Beechcraft King Air 200 tried to land at the airport of Mostar, in southern Bosnia, in bad weather.

Trajkovski, 47, six of his closest advisers and the two pilots died instantly. Their charred bodies were found in the wreckage the next day after an intense search by local authorities and Nato-led peacekeepers.

There was speculation just after the crash that the presidential plane might have been the subject of a deliberate attack.

In 2012, a family lawyer for a presidential adviser who was killed in the crash, Ignjat Pancevski, told local media that the plane was shot down by a military aircraft and that Trajkovski, his aides and the crew were killed on the ground.

As a result, the Macedonian government ordered local prosectors to open a new investigation and asked Bosnian authorities to do the same.

Kulic said on Saturday that the Mostar airport - where a French contingent of Nato-led peacekeepers assured air control at the time - did not have a working radar and that the pilots should not have tried to land there.

"The pilots should have simply directed the plane towards Dubrovnik (on the southern Adriatic coast) or Sarajevo," he told reporters.

Another official added that Macedonia's agency for civilian air transport had authorised the flight although the plane had not undergone regular technical maintainance.

The plane crashed some 10km from Mostar in a mountainous region littered with mines left over from Bosnia's 1992-1995 war.