Line worker in New Brunswick

NB Power crews were faced with a new round of outages after severe thunderstorms hit the Fredericton area early Wednesday. (CBC)

The head of Fredericton's EMO says it could take the city years to recover from post-tropical storm Arthur.

"Damage is widespread and recovery is extensive," director Wayne Tallon said in a statement on Wednesday.

He asked for citizens to be patient, calling it the single biggest cleanup operation in the city's history.

"It will take weeks, if not months, and years, to get this city back to pre-Arthur condition," Tallon said.

Meanwhile, NB Power crews are still working to restore power outages caused by the storm's high winds and heavy rains on July 5.

They had managed to whittle down the number of customers without power to fewer than 1,000 on Tuesday night, but a thunder and lightning storm early Wednesday morning sent outage numbers soaring again.

The number of homes and businesses without power was about 750 when the storm hit around 6 a.m., and the number of outages jumped to almost 2,000 by 7:30 a.m., and more than 4,000 by 9 a.m.

NB Power had tweeted that the outages were temporary, and those affected should be restored later Wednesday.

By about 6:15 p.m., NB Power's outage page showed 639 outages in the province, with about 397 of those in the Fredericton area.

The other outages are in Woodstock, with 106 customers without power, Shediac, with 98, and smaller outages in Moncton, St. Stephen, Rothesay and Miramichi.

David McKinley, Fredericton's assistant deputy fire chief, reminded people to stay away from trees on power lines as NB Power crews battle another round of outages.

"When a tree is touching a high tension power line, it will be charged right down to the ground, so we want people to stay clear," said McKinley.

"We'll go and make the area safe and tape it off if we have to."

McKinley said NB Power crews can be delayed in getting to such a scene simply by the number of outages.

At the peak of power outages, when post-tropical storm Arthur brought heavy rain and high winds to the province on July 5, NB Power had 140,000 customers without power. The Fredericton area was hardest hit in terms of power outages, with thousands of trees uprooted or breaking and becoming entangled with power lines.

The utility achieved its goal of having electricity restored to 99 per cent of those who lost it from Arthur by midnight Tuesday, only to have the number jump again Wednesday morning.