The pilots of a jet which crashed in Russia killing Polish president Lech Kaczynski and 95 others repeatedly ignored automatic alerts they were flying too low, a Polish investigator said Wednesday.

Investigator Edmund Klich told Poland's Rzeczpospolita daily that the crew "failed to react to automatic signals: the warning 'terrain ahead' or 'pull up'. These were ignored."

Russian Foreign Minister Sergei Lavrov on Thursday doubted Iran would fulfill the terms of a deal brokered by Brazil and Turkey aimed at resolving the Iranian nuclear crisis.

"There are no 100 percent guarantees. Very much will depend on how Iran will approach its commitments. If it strictly abides by them, Russia will actively support the scheme proposed by Brazil and Turkey," Lavrov said.