A major earthquake hit a region near the Iran-Pakistan border today, killing at least 34 people in Pakistan. The number of people killed and injuried in neighbouring Iran wasn't clear after conflicting reports in local media.

Earlier reports said Iran's seismological centre pegged Tuesday's earthquake at a magnitude 7.5, but that was changed to 7.7 later in the day.

The U.S. Geological Survey put the preliminary magnitude at 7.8. Initially the USGS pegged the depth at 15.2 kilometres, but that was later revised to a depth of roughly 80 kilometres.

At least 34 people were killed in a single village in Pakistan, a military official said. But the overall death toll became clouded after conflicting reports from Iran.

At first, Iran's state-in Press TV said at least 40 people died — which would push the two-nation tally to 74. But it later retreated from its account, and other Iranian outlets stepped in with a far less dire picture.

The discrepancies and apparent backtracking in the Iranian reports could not be immediately reconciled, but given last week's quake in Iran that killed 37 people, authorities could seek to downplay casualties this time out, The Associated Press reported.

Foreign Affairs Minister John Baird offered condolences to the people of Iran and Pakistan following the quake.

"The people of Iran and Pakistan are resilient when faced with adversity, and it is our hope they recover quickly from this devastating event," Baird said in a statement.

Homes, shops collapse

A Pakistani police officer, Azmatullah Regi, said nearly three dozen homes and shops collapsed in one village in the Mashkel area, which was the hardest hit by the quake. Rescue workers pulled the bodies of a couple and their three children, aged five to 15, from the rubble of one house, he said.

The Pakistani army ordered paramilitary troops to assist with rescue operations and provide medical treatment. Additional troops are being moved to the area, and army helicopters were mobilized to carry medical staff, tents, medicine and other relief items.

In Iran, the Red Crescent said it was facing a "complicated emergency situation" in the area with villages scattered over desolate hills and valleys.

The centre said the quake was centred near Saravan, a sparsely populated area about 48 kilometres from the Pakistani border.

The quake was felt over a vast area from New Delhi — about 1,500 kilometres from the epicentre — to Gulf cities that have some of the world's tallest skyscrapers, including the record 828-metre Burj Khalifa in Dubai. Officials ordered temporary evacuations from the Burj Khalifa and some other highrises as a precaution.

"The epicentre of the quake was located in the desert, and population centres do not surround it," an Iranian crisis centre official, Morteza Akbarpour, was quoted as saying by the Iranian news agency Isna. "There were no fatalities in the towns around the epicentre."

Evacuations ordered

Carla Friesen, a Canadian and a teaching assistant at the Aramco Oil Compound in Ras Tanura, Saudi Arabia, told CBC that she felt the impact of the earthquake while studying at the home she shares with her husband, Randal, and daughter Greta, 10, and son Oliver, 8.

"I was sitting on the couch doing my Athabasca University course [online] and I felt the slight tremor. Oliver felt his desk rumbling at school and his pencil fell off his desk."

A resident in the quake zone, Manouchehr Karimi, told The Associated Press by phone that "the quake period was long," and occurred "when many people were at home to take a midday nap."

Last week's 6.1-magnitude quake hit about 96 kilometres southeast of Bushehr, the site of Iran's reactor.

In 2003, about 26,000 people were killed by a magnitude-6.6 quake that flattened the historic southeastern Iranian city of Bam.

CBC meteorologist Johanna Wagstaffe, who has a background in seismology, said both the 7.8 quake today and the April 9 quake occurred on the same plate boundary.

"That is the same collision area where two tectonic plates are pushing into each other. The same forces at play that created the Zagros mountain chain in Iran," Wagstaffe said.

Because the quakes happened about 1,000 kilometres away from each other, Wagstaffe said it wasn't likely that one triggered the other.

"Perhaps there was some stress transference as a result of the first quake but it will take much more research to say with any confidence."

Wagstaffe said small to moderate size quakes are very common in the area, but she noted that the 7.8 quake is the "largest quake the area has seen in around half a century."