WASHINGTON (CNN) — The nation’s largest pilots’ union is asking the government to ban shipments of lithium batteries on all passenger and cargo planes, saying the batteries appeared to have erupted in smoke or flames on three planes in the last two months.But the union is not recommending that passengers be prohibited from boarding planes with the batteries, which are commonly found in laptop computers, cell phones, cameras and other electronic devices.The Air Line Pilots Association (ALPA) said it was prompted to call for a ban on shipments of lithium batteries by incidents onboard recent flights in Minnesota, Hawaii and the Dominican Republic. The union did not release details of the incidents, including whether the incidents occurred on passenger or cargo flights.ALPA President John Prater said he wants an “immediate ban” on lithium battery shipments until safety regulations are in place and can be enforced.“If we are not able to secure these protections for the traveling public through swift regulatory action, we will ask Congress to immediately intervene,” he said.