Heavy rain in Japan’s Kyushu Island has hampered rescue efforts in regions affected by two earthquakes in Kumamoto Prefecture —one on Thursday and the second on Saturday — that have killed at least 28 people so far, public broadcaster NHK reported. Several buildings were destroyed in the earthquakes while a report by NHK said that at least 760 people were injured.

According to a report by Jiji Press, the terminal building of Kumamoto Airport was shut down after a part of the building collapsed. Flights scheduled to leave and arrive at the airport were cancelled Saturday while the report added that the flight control room’s equipment also suffered damage due to the tremors. However, the runway was reportedly intact.

According to Jiji Press, massive landslides in the region have also cut off  two major traffic routes – Kyushu Railway Co.'s Hohi Line and National Route 57. A part of the Oita Expressway in the city of Yufu also suffered damage while several other roads and railway lines were severely damaged.

The 7.3 magnitude earthquake early Saturday killed at least 19 people in the Kumamoto Prefecture. The total death toll since Thursday, when the first earthquake of magnitude-6.4 struck the region, stood at 28. Several aftershocks followed and experts have warned of more. John Bellini, a geophysicist with the U.S. Geological Survey, said, according to the Japan Times: “We would not be surprised to see more earthquakes of this size.”

Japan's Prime Minister Shinzo Abe said, according to Reuters, that it was highly important to complete rescue work soon, due to a forecast for rain overnight, which could further cause damage by weakening the building structures and cause more landslides.

"Nothing is more important than human life and it's a race against time," Abe said, according to Reuters, after a meeting with government officials following the second quake, adding: "I want rescue activities to continue with the utmost effort."

The Reuters report also cited a local news network to say that 11 people were trapped in a university apartment in the town of Minami Aso while NHK reported that some people were trapped in a nursing home in Mashiki town. Television reports showed fires, power outages, collapsed bridges and gaping holes in the earth while people residing near a dam were told to evacuate over fears that it may crumble.

"I don't mind standing in line. I'm just thankful for some food," an elderly man seen standing in a queue for food being distributed by Self Defense Forces personnel in Mashiki said, according to Reuters. 

Meanwhile, work at factories of Sony Corp and Honda Motor Co was halted as the companies assessed the damage caused in the facilities.

Chief Cabinet Secretary Yoshihide Suga said, according to Reuters: "We are making every effort to respond," and added that about 80 people were believed to have been trapped or buried in rubble. Up to 20,000 troops were due to arrive by Sunday while more police officers, medics and firefighters were also set to be sent to the region.

In March 2011, an earthquake of magnitude-9 struck the Tohoku region in Japan’s Honshu Island, leading to a massive tsunami that caused the meltdown of reactors at Fukushima No. 1 nuclear power station. About 20,000 people were killed as a result of the tsunami.