Police said Tuesday's blasts in Ankara, Istanbul, the Aegean coastal city of Izmir and the southern city of Adana targeted branches of the British-based banking giant HSBC and an organisation with links to the United States.

The explosions were caused by percussion bombs, designed to make a loud noise rather than cause major damage.

No group immediately claimed responsibility for the blasts, but underground left-wing organisations have in the past carried out similar attacks in Turkish cities.

A security guard sustained a slight foot injury in the blast near a HSBC branch in Izmir, Turkish-news agency Anatolia reported.

Blasts last year in Istanbul left
61 people dead

Similar blasts in front of HSBC branches in Adana and Istanbul blew out windows, but caused no casualties.

The attack in the capital Ankara took place in the garden of the Turkish-US Association on a central street.

No one was injured, but the blast blew out the windows of the association building as well as a government building next to it.

Powerful blasts had hit HSBC's Turkish headquarters, the British Consulate and two synagogues in Istanbul last year, killing 61 people.