Huge Iran earthquake kills hundreds and injures thousands
At least another 2,530 were injured in the 7.3-magnitude quake that hit late Sunday, state television reported the office as saying.
A previous toll stood at 207 dead and 1,700 wounded.
The earthquake was felt across the western provinces of Iran but hit hardest in Kermanshah, which announced three days of mourning.
More than 236 of the victims were in Sarpol-e Zahab county in Kermanshah province, about 15 kilometres from the Iraq border.
Iran's Supreme Leader Ayatollah Ali Khamenei offered his condolences on Monday, urging all government agencies to do all they could to help those affected.
More than 70,000 people were in need of emergency shelter, the Iranian Red Crescent said.
Turkey dispatched emergency personnel and aid to northern Iraq after the earthquake as officials expressed "deep sadness" at the tragedy.
Iranian state television also quoted Iraqi officials as saying that at least six people had been killed in the neighbouring country.
The officials added that over 50 people had been injured in Iraqi Kurdistan's Sulaymaniyah province and around 150 in Knaquin city.
Tremors were reportedly felt as far away as the United Arab Emirates.
According to the US Geological survey, the earthquake's epicentre was around 20 miles southwest of the Iraqi city of Halabjah. Iranian authorities, meanwhile, said a 7.3 magnitude earthquake had hit Azgaleh city in Kermanshah.
The USGS issued an "orange", warning of possible "shaking-related fatalities and economic losses."
It is feared that the number of casualties will rise as emergency services sift through the disaster zones, especially in rural areas where many live in non-sturdy mud brick houses.
Esmail Najar, head of Iran's National Disaster Management Organization, warned that "some injured people might be buried under the rubble in Ghasr-e Shirin".
Earthquake are an almost daily occurrence in Iran, which sits on many of the earth's major fault lines.
Last month, a 5.2-magnitude earthquake jolted Iran's southern Kerman province, however no casualties were reported.
In 2003, around 26,000 people were killed in the city of Bam, which was levelled by a 6.6 magnitude earthquake.