PESHAWAR - A pressure cooker bomb hit a police van protecting a polio vaccination team here on Monday, killing two people.

The attack took place on the third and last day of a UN-backed vaccination campaign in a suburb of the city of Peshawar, police said, adding that a policeman was among the two dead.

Pakistan is one of only three countries in the world where polio is still endemic, but efforts to stamp out the crippling disease have been hit by repeated attacks on health teams.Militant groups in the restive country have rejected vaccination as a Western plot and banned teams from giving out polio drops in some areas.

"It was an IED blast and the target was policemen," Najeebur Rehman, a senior police official told AFP, adding that the bomb went off just as officers reached the village to provide security to polio teams.

Nasir Durrani, police chief for northwestern Khyber Pakhtunkhwa province, of which Peshawar is the capital, confirmed the incident and death toll and said most of the 12 wounded were policemen.

Abdul Haq, a senior bomb disposal expert, said the bomb was made from a pressure cooker, with metal and nails added as shrapnel.

Authorities said a second device was defused close to the site of the first blast and they had halted polio vaccination in Badaber village, where the incident took place. "A second bomb with five kilograms of explosives has been defused. We have suspended the campaign for time being," Zahurul Islam, a senior government official in Peshawar told AFP.

Islam said the outer wall of the government-run clinic collapsed due to the intensity of the explosion.

Islam said all those wounded in the blast were policemen, adding that a total of 54 polio workers including 24 women were present inside the clinic. Raheel Shah, another police official, told AFP that polio workers remained safe in the attack, adding that the second person killed in the blast was a volunteer from the village community police. Polio teams also came under attack in Karachi and in the northwest last year, with the killing of nine health workers carrying out vaccinations.

President Mamnoon Hussain and Prime Minister Muhammad Nawaz Sharif have strongly condemned the blast.

Deploring the loss of precious lives‚ the President directed the authorities concerned to provide best medical treatment to the injured.

The Prime Minster has lauded the security personnel who laid down their lives in the line of duty. Governor Khyber Pakhtunkhwa Engineer Shaukatullah has also strongly condemned the blast.

The Prime Minister paid highest tributes the personnel of law enforcing agency who sacrificed their lives in the line of duty. He prayed to Allah Almighty to bless the departed souls with eternal peace and grant courage to the bereaved families to bear this irreparable loss with fortitude.

He also prayed for the early recovery of those injured in the blast.

Meanwhile, a spokesman for the Jundullah group Ahmed Marwat, a faction of the Pakistani Taliban claimed responsibility for the attack.

The attacks were said to target law enforcement agencies.

The deceased were identified as Niaz Gul son of Khial Gul, Sajid Hussain son of Abdul Jamil resident of Charsadda while the injured were identified as Alam Zeb son of Zahid, Asifullah son of Habibur Rehman, Fida Mohammad son of Sheikh Zaman, Hakeem son of Bakht Biland, Imran son of Faqir Muhammad, Irfanullah son of Rizwanullah, Javed Khan son of Shamsudin, Zikiria Ahmad son of Anwar Khan, Rashid Khan son of Shereen, Shakar Gul son of Taza Gul, Umar son of Muhammad Din and Zaiwar Khan son of Abdul Baqi.