The attacks highlight the risk for the vaccination teams and their police guards in Pakistan which is among the three countries where the polio virus persist, Xinhua reported.
Vaccination campaign was suspended in parts of Karachi after the two attacks in different locations within 15 minutes, officials said.
Gunmen riding motorcycles sprayed bullets at the police mobile teams, a police officer Fairoz Shah told reporters. The gunmen fled after the attacks.
The authorities had launched a three-day polio vaccination drive in Karachi on Monday and the attacks occurred on the last day of the campaign. Health officials had planned to administer drops to nearly 2.2 million children in Karachi.
The Pakistani Taliban splinter Jamaat-ul-Ahrar group claimed responsibility.
“We have carried out both attacks on the polio teams in Karachi,” spokesman for the TTP JA Ehsaullah Ehsan told the local media over phone. He said the attacks were part of the group’s activities across Pakistan.
The group, which the officials say operates from the Afghan side of the border, has claimed several recent attacks.
The TTP JA had also claimed responsibility for the suicide attack on the excise office in Mardan on Tuesday that killed at least one person and injured 17 others.
Last month the group’s bomber killed nearly 70 people at a park in Lahore.