A Russian rocket carrying 18 satellites has crashed soon after lift-off from the Baikonur cosmodrome in Kazakhstan.
According to mission control officials, the engines of the Dnepr rocket shut down 86 seconds into its flight.
The rocket crashed some 25km (15 miles) away, without causing injuries on the ground, but all of the 18 satellites on board were destroyed.
Seventeen of the satellites were being launched for foreign customers, including the US and Italy.
One of those was to have been the first satellite operated by Belarus, whose president, Aleksander Lukashenko, had gone to Baikonur to see the launch, local media reported.
"A special emergency team has been formed to probe into the causes of the failed launch," said a spokesman for the Russian space agency Roskosmos, quoted by Itar-Tass news agency.
"According to preliminary findings problems in the first stage of the booster rocket in the 74th second of the flight was the main reason," Igor Panarin said.
Last October, a Russian rocket crashed while carrying a European satellite that was to have monitored the thickness of the Earth's polar ice.
Baikonur is the world's largest space centre.
After independence, Kazakhstan agreed to lease the site to Russia. That lease now extends until 2050.