Poland is to hold seven days of mourning after President Lech Kaczynski, his wife, and an official delegation of senior officials were killed in a plane crash in western Russia.
"I have just signed a decision on the announcement of a national week of mourning," acting president and parliamentary speaker Bronislaw Komorowski said.
"We must all come together in the face of this massive national tragedy," he added. "Today, there is no left wing and no right wing - there is no difference. We all feel for the families of the dead."
Polish Prime Minister Donald Tusk and Russian Prime Minister Vladimir Putin are currently on their way to the site of the crash.
The Soviet-made Tu-154 hit trees as it approached Smolensk airport in thick fog.
Kaczynski was on his way to a ceremony in nearby Katyn to commemorate the memory of some 20,000 Polish officers killed by Soviet secret police during World War Two.
WARSAW, April 10 (RIA Novosti)
