Three suspects have been detained for making bomb threats that caused flight delays in the past week, the Ministry of Public Security announced on Saturday.

The suspects, named Tan, Xie and Wang, stand accused of making three bomb threats, on Oct 27, 28 and 31, the ministry said in a statement.

The police did not say whether the suspects and cases were connected.

The suspects confessed to the offenses during interrogation, authorities said in a statement.

Changsha Huanghua International Airport in Hunan province received a phone call on Oct 27 saying there was a bomb on an airplane, and Fuzhou Changle International Airport in Fujian province received a similar threat on Oct 28.

On Oct 31, a man phoned Changsha Huanghua International Airport twice, saying there were bombs on a number of airplanes.

In the statement, the ministry vowed to deal with such cases severely and speedily, saying that such acts threaten aviation and human life, as well as disrupt public order.

Under criminal and civil aviation laws, intentionally disrupting flights with hoaxes is punishable by prison sentences of up to five years. The sentences can be longer if the hoax has serious consequences.

Recently, there have been several bomb threats of planes in China. Six cases between May 15 and 18 caused plane diversions, emergency landings and delays to 22 flights in Beijing, Shanghai and Guangzhou.