By Ruma Paul and Sudarshan Varadhan

DHAKA (Reuters) -Bangladesh could face further power cuts due to higher demand, its power minister said, as a fuel shortage sparked shutdowns of several power generating units including its biggest coal-fired plant.

The country has faced disruptions to electricity supply due to erratic weather this year, with soaring temperatures pushing up demand in April and a deadly cyclone cutting off supplies of natural gas to power plants the following month.

On Monday, the 1.32 gigawatt (GW) Payra plant in Bangladesh's south also closed its second unit due to a coal shortage, having shut one unit on May 25.

Nasrul Hamid, minister of state for power, energy and mineral resources, said Bangladesh is looking to restart the plant by the last week of June.

"There is no alternative other than to cope with the shortage," Hamid told Reuters. "We will have to bear with this for another two weeks."

Maximum temperatures in capital Dhaka rose to nearly 38 degrees Celsius (100.4 degrees F) on Sunday, compared with 32 degrees ten days earlier. The weather office has warned that the ongoing heatwave is likely to continue for the rest of this week.

When demand peaked at noon on Monday, it outstripped supply by 18%, a senior power ministry official told Reuters. The shortfall came a day after Bangladesh's total power deficit rose to its highest in three weeks.

"Only rain can give us some relief as power demand decreases when it rains," said the official, who declined to be identified as he is not authorized to speak to the media.

The power losses threaten Bangladesh's apparel sector, which accounts for more than 80% of its exports and supplies retailers such as Walmart, Gap Inc, H&M, VF Corp, Zara and American Eagle Outfitters.

The loss of those exports will exacerbate issues around its dollar reserves, which have plunged by nearly a third in the 12 months to the end of April to a seven-year low, limiting its ability to pay for fuel imports.

The frequent power cuts have drawn criticism.

"The entire country is almost without electricity. People are getting sick in extreme heat," said Ruhul Kabir Rizvi, a senior leader of the main opposition Bangladesh Nationalist Party.

"There is no electricity for 10 to 12 hours every day. Electricity goes off at night, nobody can sleep,” said Mohammad Sharif, a private sector employee, on the outskirts of the capital.

(Editing by Christian Schmollinger and Jan Harvey)