Lahore: At least eight persons were injured when a bomb went off at a police post in Multan city in Pakistan's Punjab province, officials said.

Officials had initially said three policemen were killed in the attack but later revised the account after it became clear that no one had died.

Multan police chief Amir Zulfiqar said three policemen were among the injured and that no one was killed.

Preliminary investigations indicated that the blast was caused by a bomb planted in a motorcycle, Zulfiqar told the media at the site of the attack.

Earlier, district administration chief Zahid Zaman had said that the attack was carried out by a suicide bomber but this was dismissed by Zulfiqar.

Two suspects being held at the police post escaped after the blast, reports said. The post on the busy Multan-Lahore highway is located near residential and commercial areas. The blast, which was heard from several kilometers away, destroyed a wall of the police post and damaged nearby houses. No group claimed responsibility for the attack.

Prime Minister Yousuf Raza Gilani, who belongs to Multan, condemned the terrorist act and said it was "a cowardly act of a sick mindset".

He said: "The terrorists are targeting police stations to create panic and fear among innocent citizens in cities."

The government and people of Pakistan are "determined to fight terrorism and eliminate such elements who want to create instability and spoil the image of the country", he said.

Gilani directed security agencies to take appropriate measures in all cities and towns to prevent any possible act of terror.