A blast has been reported in the southern Afghan city of Kandahar, a day after the country's deadliest bombing for a year killed some 43 people there.
The explosion was reported close to the site of Tuesday's car bomb attack.
There are reports of casualties. A local official told the BBC the injured were being taken to hospital.
Kandahar, a Taliban stronghold, has seen a number of attacks in 2009. It comes as counting continues following last week's presidential election.
"This is a terrorist attack but we are trying to find out more details," a senior government official in the city told the BBC.
Footage taken half a kilometre from the scene showed flames
"It's very dark and confusing to understand what happened. But our forces are out on the streets."
The blast was said to have happened next to Kabul Bank.
Shops were in flames next to the building, an al-Jazeera journalist reported from the city, and mobile phone footage sent to the BBC shot from a location 500m (a third of a mile) from the scene showed a fire burning.
Rescuers are still searching for survivors in the rubble of buildings destroyed in Tuesday's attack, which left more than 60 people injured.
The explosion struck close to the offices of the Kandahar provincial council. Windows across the city were shattered by the force of the blast.
Several buildings were destroyed by the force of Tuesday's blast
Some reports said bombs were packed in cars that exploded simultaneously, others that a truck or tanker had been used.
There have been a series of insurgent attacks across the country as Afghanistan held its presidential election.
The Nato-led International Security Assistance Force (Isaf) said there were more than 400 attacks on election day alone.
Four US soldiers were also killed in fighting on Tuesday, making 2009 the deadliest year for foreign troops in Afghanistan since the 2001 US-led invasion.
Latest results in the presidential poll show incumbent Hamid Karzai extending his lead over former foreign minister Abdullah Abdullah.
Fewer than a fifth of votes cast have so far been counted amid allegations of widespread fraud.