Germany on Tuesday warned its citizens to avoid crowds and tourist sites in Istanbul after 10 people were killed and 15 wounded in a suspected terrorist attack in Turkey’s largest city.

Germany on Tuesday warned its citizens to avoid crowds and tourist sites in Istanbul after 10 people were killed and 15 wounded in a suspected terrorist attack in Turkey's largest city.

"Travelers in Istanbul are strongly urged to avoid for now large groups of people in public places as well as tourist attractions and to stay abreast of the situation via these official travel advisories and the media," the foreign ministry said.

Ten people were killed and 15 wounded in a terrorist attack on Tuesday in the main tourist hub of Turkey's largest city Istanbul, officials said.