German Chancellor Angela Merkel will miss the opening of the G20 summit in Argentina after her plane was forced to land shortly after leaving Berlin.

Her office says Mrs Merkel and delegates made a safe, but unscheduled, landing in Cologne after the Airbus developed a technical problem.

The plane turned back while it was flying over the Netherlands.

Mrs Merkel flew to Madrid on Friday before taking a scheduled Iberia airlines flight to Buenos Aires.

The captain announced to passengers on Thursday evening that he had decided to turn back after the "malfunction of several electronic systems".

The plane's communications system went down and the crew had to use a satellite phone to contact air traffic controllers, Germany's Spiegel website reported. The problem is thought to have been with an electronic distribution box, which controls both the radio and discharge of aviation fuel.

The German air force denied suggestions that the plane's electronics could have been sabotaged. "There's is absolutely no indication of a criminal background," a spokesman said.

An added problem for the plane was that Cologne airport's longer runway was unavailable, Spiegel added. As the A340 had to slow down quickly and it was still fully laden with fuel, its braking system overheated and the fire brigade met the plane on the tarmac.

The German delegation was kept on the plane for some time before officials decided to travel by bus to a hotel in Bonn.

The chancellor and a smaller delegation including the finance minister travelled to Madrid on an air force plane on Friday morning before leaving for Argentina on an Iberia plane, a spokesman said. Mrs Merkel's husband was among those on the initial flight who remained in Germany.

Although there is a standby government plane for long-haul flights, no crew was available to fly it, German media report. Organising an alternative route proved a headache for the German government, as Mrs Merkel's entourage had to include several security officials.

The chancellor will miss the "family photo" at the start of the G20 summit and it is unclear if key bilateral meetings with national leaders can be rescheduled. She had been due to have talks on Friday with President Donald Trump and China's Xi Jinping.

The Airbus A340-300 hit by technical failure is named Konrad Adenauer after West Germany's first post-war chancellor.

For finance minister Olaf Scholz, the plane's technical problems are nothing new.

In October he was on a trip to Indonesia when the plane was grounded because rodents had gnawed through electrical cables during an annual meeting of the International Monetary Fund (IMF).

Last month, President Frank-Walter Steinmeier arrived late for a trip to South Africa because one of the plane's engines would not start.