JALALABAD, Afghanistan, Oct. 2 (Xinhua) -- At least seven people were killed and 25 others wounded after a suicide bombing ripped through an election rally in Afghanistan's eastern province of Nangarhar on Tuesday, a local official said.

"The incident occurred at a parliamentary election candidate at around mid-day in Kama district in east of provincial capital Jalalabad city. The number of casualties may change as several wounded were in critical condition," the official who declined to be named told Xinhua.

Security forces have cordoned off the area for precautionary measures.

The casualties were shifted to nearby hospitals by ambulances and police vehicles.

Further details about the incident are still forthcoming amid the absence of any official statement.

The electoral campaign for the Oct. 20 Afghan parliamentary and district councils elections began Friday across the country.

Around 2,691 candidates from 33 out of 34 provinces (excluding Ghazni) will stand for the parliament's 249 seats, another milestone in the war-torn country's electoral history.

More than 50 people, including seven election candidates, have been killed in election-related attacks and explosions across the country since early this year.