Two powerful earthquakes have killed at least 220 people and injured around 1 500 in north-west Iran, Iran's state news agency has reported.
Mohammad Khatami said on Wednesday trial confessions by moderates accused of fomenting post-election unrest were invalid.
A senior Iranian official said Tehran was ready for negotiations with the West on its disputed nuclear programme, according to reports on Tuesday.
The West must be held to account for stoking Iran's post-election unrest, the president said on Sunday, as a third mass trial got under way.
Iran put dozens of moderates and a French citizen on trial on Saturday for taking part in unrest after a disputed June presidential vote.
At least 17 people were killed and 23 injured when a passenger aircraft veered off the runway and hit a wall while landing at Mashhad airport.
A Tupolev passenger aircraft crashed in north-western Iran on Wednesday, killing all 168 people on board, Iranian media reported.
Iran is running more than 5 000 centrifuges for enriching uranium, its president was quoted as saying on Saturday.
Iran will not give up its rights in the face of Western pressure, its supreme leader said on Sunday, two days after major powers said they would make a new offer to convince Tehran to halt its nuclear plans. Ayatollah Ali Khomenei did not explicitly mention Iran's nuclear activities, which Western powers suspect are aimed at making bombs.