Chemical explosions have been reported in Japan, which has the world’s most extensive chemical arsenal.

According to Japanese media, one explosion on Sunday caused an explosion in a hospital, but the exact cause is still unknown.

There were also reports of an explosion at a public hospital in the city of Chiba, which is about 150 kilometres (90 miles) east of Tokyo.

The government said no casualties were reported.

In April, Japan recorded a series of deadly explosions that prompted a series to be conducted by a US company called Xtreme Safety.

Japanese officials said that after the first explosion, the company, Xtres Safety, called in X-rays of the damaged area to determine if the source of the explosion was a person or an object.

At least 17 people were injured in the explosions, which were not linked to any specific product.

Japan has some of the world`s most extensive stockpiles of toxic chemicals and weapons, and has been in a state of emergency since the April 7 earthquake and tsunami.

“There are reports of chemical explosions at a number of hospitals,” said Toshihiko Otsuka, a senior official at the health ministry.

Some hospitals reported “severe” damage and many were not able to reopen for several days.

Officials said the explosions occurred at three public facilities, including hospitals, schools, and the main shopping mall.

One hospital in Chiba reported that “a number of patients and staff were treated for chemical effects”, according to a government statement.

Another hospital in Tokyo said that “several buildings were destroyed and that the injured were taken to nearby hospital”.

An explosion was also reported at the main hospital in Shinjuku, which houses about 30,000 people, according to media reports.

Tens of thousands of people attended the rally.