Police say vaccination drive will continue despite the attack.
Gunmen on Monday killed a policeman guarding a polio vaccination team in Karachi, police officials said, the latest blow to efforts to stamp out the crippling virus in Pakistan.
The attackers on a motorbike shot the policeman in Papoosh Nagar and then fled, said senior police official Chaudhry Asad. The vaccination drive remained unaffected by the shooting, he added. Another police official confirmed the attack and casualty.
Pakistan is one of only three countries where polio remains endemic. Attempts to eradicate it have been badly hit by opposition from militants and attacks on immunization teams that have claimed 68 lives since December 2012.
The militants claim that polio vaccination is a front for espionage or a conspiracy to sterilize Muslims.