Image copyright Reuters Image caption Paramilitary police sealed off the area around Sunday's blast

A man has set off a homemade explosive device at Shanghai international airport, injuring four people as well as himself, Chinese officials say.

The attacker threw a bottle containing explosives, which went off near a check-in counter in Terminal Two.

The man then took out a knife and stabbed his own neck, officials say.

In 2013 a man in a wheelchair detonated a bomb at Beijing airport to highlight a personal grievance. He was later sentenced to six years in prison.

The latest incident happened at about 15:00 (07:00) on Sunday.

Eyewitness Ni Bowen told the Associated Press news agency that she was waiting to check in at Pudong International Airport when there was a loud bang.

"A beer bottle filled with white smoke rolled right by my feet. I was scared and made off at once,'' she said.

The four victims sustained light wounds and are being treated in hospital. The unnamed attacker is said to be in a critical condition.