One man has been killed and three members of his family have been wounded in an explosion in Cairo, according to Egyptian officials.

The blast on Friday in the Maadi district, caused by a "unidentified metallic object", killed a 35-year-old building guard as he cleaned a garden, the interior ministry said in a statement.

His wife and two sons were wounded by shrapnel in the explosion and were taken to hospital for treatment, the ministry said.

The area had been cordoned off and was being combed by security forces, it added.

There was no immediate claim of responsibility.

Maadi is a large district that houses embassies and foreigners, as well as middle and working class areas.

The site of the explosion was not close to any embassies, some of which had been threatened by armed groups over the past few years.

Source: News agencies