Casualties were feared as a suicide car bomb targeted the provincial intelligence office building in Jalalabad city, the provincial capital of eastern Afghan province of Nangarhar, early Saturday morning, source said.
"A suicide car bomb hit the gate of Nangarhar's National Directorate of Security (NDS) at around 4:50 a.m. (local time). The blast caused casualties but details will be released to the media later on Saturday," a provincial government spokesman, Ahmad Zia Abdulzai, told Xinhua.
Unofficial sources said 30 people were killed and injured in the incident in the city, 120 km east of Afghan capital of Kabul.
The force of the blast damaged several buildings near the sites and shuttered the windowpanes of dozens of houses.
Following the attack, the Taliban insurgent group claimed the responsibility for the attack. A purported Taliban spokesman, Zabiullah Mujahid, told local media that several Taliban suicide bombers and gunmen were involved in the attack. He said several security forces were killed and injured following the attack.
A surge in attacks has been witnessed in the country since mid- May, when the Taliban launched a yearly rebel offensive against Afghan security forces and more than 44,000 NATO-led troops stationed in the country.