A man rows a boat in the Bosphorus strait amid heavy fog in Istanbul, Turkey, Feb. 21, 2019. Heavy fog hit Turkey's largest city Istanbul on Thursday, causing hundreds of flights and ferries to be canceled or delayed. (Xinhua/Xu Suhui)

ISTANBUL, Feb. 21 (Xinhua) -- Heavy fog hit Turkey's largest city Istanbul on Thursday, causing hundreds of flights and ferries to be canceled or delayed.

The Turkish Airlines, the national flag carrier, advised its passengers to regularly check their flight status before departing for the airports, citing "adverse weather conditions."

The Pegasus Airlines announced that all of its flights to and from the Sabiha Gokcen Airport located on the Asian side of Istanbul were affected by the thick fog.

Meanwhile, the city-line ferry agency canceled all the ferry services for the day due to the extremely poor visibility in the Bosphorus Strait and the Marmara Sea, resulting in a heavy land traffic during the morning rush hour.

Experts said the visibility was reduced to 10 meters in some locations.