Afghanistan's deadly year continues with suicide bombing in Jalalabad government building
Heavy casualties are feared in the attack, which marks the latest instance of violence in the war-torn country.
A BBC investigation published on Tuesday revealed Afghanistan is now the world's deadliest conflict after a month of carnage in August, when an average of 74 people were killed every day.
Witnesses and an AFP reporter also described hearing gunshots immediately after the blast at the city's electronic identification registration centre.
Both the Taliban and the Islamic State extremist groups are active in Nangarhar province, of which Jalalabad is the capital.
No group immediately claimed the attack.
"Security forces are in the area to rescue the staff," said provincial spokesman Ataullah Khogyani.
The suicide blast came just a day after the Taliban killed almost 50 people and wounded dozens more in two seperate attacks, one near a campaign rally for President Ashraf Ghani in the central province of Parwan, and one in Kabul.
Taliban militants have vowed to disrupt the country's upcoming presidential election, scheduled for 28 September.
The winner is hoping for a mandate to negotiate with the Taliban for a lasting peace.
But the insurgents want to undermine the legitimacy of the process and keep the president weak.
"We already warned people not to attend election rallies. If they suffer any losses that is their own responsibility," Taliban spokesman Zabihullah Mujahid said in a statement released after Tuesday's blasts.
They have also promised further violence after US President Donald Trump called off talks with the group earlier this month after an attack claimed by the Taliban killed a US service member.
The US and Taliban had been engaged in negotiations, said to be nearing a deal recently, towards a withdrawal of most US troops from Afghanistan.
In exchange, the extremist group were set to refute IS and al-Qaeda, and cease such attacks.
The militants have repeatedly stated they believe the US will return to the negotiating table.