MINGORA, Feb 22 Five civilians and two security personnel were killed and 37 others wounded when a suicide bomber blew himself up near a military convoy in Swat valley's main town of Mingora on Monday.

The convoy was attacked when it was passing through the busy Nishat Chowk.

After the blast, which destroyed eight vehicles and damaged a number of shops, people were seen running for safety and soon the streets were deserted.

According to agency reports, the bomber used a car packed with explosives to attack the convoy.

This was the third suicide attack in Swat since a military operation was launched in May last year. The valley which had suffered bloody clashes and subversive activities earlier has been relatively peaceful for some time.

ANP lawmaker Shamsher Ali Khan was killed in a suicide attack in December last year.

A witness of the Monday attack said there was a fireball and an explosion which rocked the entire city. The scene was littered with human limbs and injured people were lying all around.

The injured were taken to the Saidu Sharif hospital. Firemen struggled for hours to put out the fire.

AFP adds Television footage showed a car enveloped in flames and black smoke billowing down a street, as casualties lay on the ground in blood-soaked clothing. Soldiers rushed to the scene and ambulances ferried away the wounded.

Frightened women and children could be seen scurrying from the scene.

“I was going for some work in the bazaar but was stopped by security forces because the army convoy was moving,” said Saeedur Rehman, a 45-year-old teacher. Moments later, a car hit the tail end of the military convoy.

“Suddenly there was a huge blast and smoke filled the area. Then heavy firing started and I lay on the ground,” Mr Rehman told AFP.

Officials said they had seized parts of the car used by the bomber.

“Four women, two children and three men were killed,” city police chief Qazi Ghulam Farooq said, adding that four of the injured were in a serious condition.

“It was a suicide car bomb... The target was an army convoy,” Maj Mushtaq Ahmad Khan of the Swat Media Centre said.