Police in Pakistan say gunmen have shot dead two journalists in separate attacks in the country's violent port city of Karachi in the last 24 hours.

Police say the first attack Tuesday night saw gunmen open fire on a van of the private satellite news channel Geo TV, killing a technician and wounding the driver.

The second attack happened Wednesday morning. Feroz Shah, a deputy inspector-general of police, said gunmen on a motorcycle shot and killed journalist Aftab Alam as he stood outside his home. Alam previously worked with Geo TV.

It wasn't clear whether the two attacks were related or due to the fact those involved were journalists. However, Geo TV has previously been banned over a spat between it and the country's powerful Inter-Service Intelligence spy agency.