Subway service in downtown Montreal was paralyzed for 45 minutes Tuesday after public transit authorities shut down 15 stations due to communications problems.

The orange line was temporarily closed between Bonaventure and Beaubien, and the green line was shut between Lionel-Groulx and Berri-UQÀM stations because communication lines were down, the Montreal Transit Commission said.

The problem has been resolved and rush-hour service will resume gradually, but people should expect some delays and lineups, the MTC said.

Humidity-related power outages had delayed Montreal rush-hour subway service on Tuesday morning.

MTC authorities said the power outages would probably cause more problems.

Monday's hot, humid weather sparked electrical failures in the underground metro system after condensation formed on the rails.

Several slowdowns were reported on one line and more delays are expected until the tunnels are dried out, said Odile Paradis, a spokeswoman for the Montreal Transit Commission.

The situation is slowly improving because "the power outages are fewer in number and much shorter than on Monday," she said.

The power outages affected the orange line, primarily between the Bonaventure and Beaubien stations.

People who can avoid that line should try to do so, the MTC said.

Isolators protecting the electrical circuits will be cleaned overnight to try to fix the problem.

Some additional bus service was to be on hand in case there were more power outages during Tuesday's afternoon rush hour.