The United States Geological Survey (USGS) on Wednesday warned of a potential rise in eruptions from Hawaii’s Kilauea volcano in the coming weeks.

The agency also informed the public that the volcano, which has been emitting toxic gas, may spray pebble-like projectiles miles from the fissures. These are known as ballistic projectiles and their weight can range from a few pounds to several tons. These projectiles are ejected when the lava sinks into a water table inside the crater, which could create pressure causing steam explosions.

A brief explosion Wednesday was a result of rocks falling into the volcano and not an influx of lava with the water table, the USGS confirmed.

"Debris expelled during such explosions could impact the area surrounding Halemaʻumaʻu and the Kīlauea summit," the Hawaiian Volcano Observatory (HVO) told the Star-Advertiser, Fox News reported. 

In an update Wednesday, the HVO said, “At this time, we cannot say with certainty that explosive activity will occur, how large the explosions could be, or how long such explosive activity could continue.”

The authorities added ash clouds would rise to greater heights, distributing particles over wider areas. In addition, there is a potential for sulfur dioxide emission. When the gas mixes with sunlight, moisture and oxygen, it produces acid rain and volcanic smog.

“These are really high levels, and that’s why people near the volcano had to evacuate, but I have to say that, periodically, many places on the Big Island actually see levels that are way over,” said Elizabeth Tam, the lead author of the Environment International paper, told TIME.

The volcano has already forced about 2,000 residents to evacuate.

Volcanic smog is a hazy air pollution aggravating respiratory problems and causing flu, fatigue and irritation.

"Because of their small size, aerosol particles such as those in smog penetrate deep into the human lung and are readily retained," the USGS said.

Acid rain is forecasted for Thursday and Friday, and can damage buildings, metal objects and plants and contaminate water resources.

"Walking in acid rain, or even swimming in a lake affected by acid rain, is no more dangerous to humans than walking in normal rain or swimming in non-acidic lakes,” environment protection agency said, CNN reports.

Kilauea, one of the most active volcanoes in the world, began spewing lava a week ago after its increased activity was warned by number of earthquakes. The Hawaiian Volcano Observatory confirmed new fissure in Lanipuna gardens, a home to 250 people, taking the total number of surface cracks from where gas is escaping to 15. So far, 36 structures have been destroyed.

“No one lives in the immediate area of the summit crater. But people have continued to visit Hawaii Volcanoes National Park, which includes the crater and surrounding region. The park will be evacuated before conditions worsen,” officials told Fox News.