Three people were wounded by an explosion in Istanbul's Maltepe district on Monday, local media reported.
The blast is believed to have come from a suspicious package sent by courier to an electronics company.
Local news channels said that the office targetted in the attack belongs to a brother of former Turkish prime minister Mesut Yilmaz. Other reports said that the victims also included the son of Turkey's former finance minister Kemal Kurdas.
Maltepe is a commercial and residential district on the Asian side of Istanbul. Turkey has been on high alert since the past few weeks following a spate of attacks by terror groups, Daesh and PKK.
Meanwhile, at least ten people were wounded when a steam boiler exploded in a cosmetics manufacturing plant situated in Istanbul's working-class suburb of Sultanbeyli, where there are many car repair shops and small factories.