Six people have been killed and seven others wounded in a suicide bomb attack on a police checkpoint in Islamabad, the capital of Pakistan.
Kamal Hyder, Al Jazeera's correspondent in Islamabad, said paramilitary forces opened fire after the attack on the post in an upmarket residential area close to some of the capital's most prestigious addresses.
Witness Aziz-ur-Rehman told the AFP news agency he was standing across a road from the post when he heard the explosion.
"After the blast, there was intermittent firing but since it was dark I was unable to know who was firing," he said.
The bomber was believed to have targeted members of the Frontier Constabulary, part of Pakistan's paramilitary force, used to protect diplomatic missions and the homes of prominent figures.
The attack was the second fatal bombing in Islamabad in less than two weeks.
A suicide bomber blew himself up outside a special police office on March 23, killing a guard and wounding three other people on a public holiday.
PHOTO CAPTION
Pakistani paramilitary soldiers rush toward the site of the suicide bombing in Islamabad, Pakistan, Saturday, April 4, 2009.
Al-Jazeera