A Turkish news agency says assailants have fired shots at the police who guard Istanbul's Dolmabache Palace, an Ottoman-era palace that is a major tourist attraction.

The Dogan news agency says no one was hurt in the attack and the two assailants were quickly caught. It did not cite its source for the information. Dogan video footage on Wednesday showed that a road leading to palace had been sealed off by police.

Police in Istanbul had no immediate comment on the report.

The incident comes amid an escalation of violence between Turkey's security forces and Kurdish rebels and as Turkey has been conducting operations against terror groups including the Islamic State group. Turkey has rounded up more than 1,000 people linked to IS, the Kurdish rebels and leftist militants.