Several injured in attack on Istanbul bus terminal

Gunmen opened fire at commuters at Istanbul's main bus station, injuring a number of people.

Turkish news agency Anadolu reported that unknown gunmen fired at a crowd on Istabul Bus Station's first floor, according to security sources.

Early reports suggest the shooting happened following an altercation between the gunmen and station manager, whose office is located on first floor.

The number of injured was not immediately confirmed, with some reports saying the number of those hurt to be at least three, while other local media outlets reported that those wounded numbered at least seven.

The wounded were taken to hospital, and at the time of writing, no information was released on their condition.

Turkey has witnessed an upsurge in violence from Kurdish militants and the Islamic State group.

Earlier Thursday, three people were killed during a gunfight between Turkish security forces and Kurdish militants in southeast Turkey.

More than 100 people - mostly Turkish soldiers and policemen - have been killed since a two-and-a-half-year ceasefire between Ankara and the Kurdistan Workers Party ended in July.

Turkey has also witnessed a number of attacks from Leftist militants. 

Earlier this month, the US consulate in Istanbul came under gunfire in a wave of attacks later claimed by an outlawed radical Turkish Marxist group. 

The Revolutionary People's Liberation Front (DHKP-C) said on its website that one of its women militants carried out the attacks. 
 
Also in August,  Turkish police arrested two people after shots were fired at officers guarding Istanbul's Dolmabache Palace, an Ottoman-era palace.

Dolmabahce - one of the last great palaces of the Ottoman Empire and also where the founder of modern Turkey Mustafa Kemal Ataturk, died in 1938 - is one of Istanbul's major tourist attractions.
 
Turkish authorities have arrested more than 1,300 people since late July in police raids nationwide targeting suspected members of the outlawed Kurdish Workers Party (PKK) as well as IS and the DHKP-C.  

The spiral of violence sparked by the killing of 32 pro-Kurdish activists in a bombing by suspected IS jihadists in July has left a 2013 ceasefire between Ankara and the PKK in tatters.