Thousands of people left homeless by a powerful earthquake in northern Italy will be sleeping tonight in

makeshift

shelters as

aftershocks

continue to spread fear in the region. At least six people were killed and more than 50 injured. The magnitude six quake had its

epicenter

near the city of Modena. Our correspondent Alan Johnston is in a neighboring town.

Moments after we arrived, there was another aftershock. There was a sound of masonry crashing down a few streets away. In one square, an old club tower stood half-destroyed by the quake. A small crowd that gathered was looking on at the ruin. And just as we joined them, another aftershock struck. In front of us, what remained of the tower collapsed,

tumbling down

in a shower of bricks and

timbers

, and sending a great cloud of dust rolling across the square.

Three trainee skydivers taking their first jump have died along with their instructor and pilot when their light aircraft crashed shortly after takeoff from an

airstrip

in Bosnia. Bosnian police said the plane

burst into flames

. Families who had gathered to watch the jump witnessed the crash.

The government of Pakistan has lifted a nationwide ban on the social media website Twitter within hours of imposing it. No reason was given for reversing the earlier decision, which wasn't explained either. But correspondents say the ban appeared to be linked to messages posted on Twitter which were deemed offensive to Islam about a competition on Facebook in 2010, inviting users to submit images of the Prophet Muhammad.