Harald Doornbos has linked to photos of the area in Istanbul where this morning's blast is thought to have taken place, based on media reports.
AP have published a photo showing Turkish police securing an area of Istanbul's historic Sultanahmet district, a popular tourist area, following an explosion earlier this morning.
Turkish officials seem to be confirming initial suspicions that the Istanbul blast was terror related.
Meanwhile, in Syria's Latakia province, the Syrian army has made advances into the key rebel-held town of Salma.
Some sources are saying that Salma has completely fallen to the Syrian army, but this is unconfirmed as yet.
The World Health Organization has asked the Syrian government for permission to send mobile clinics and medical teams to the besieged town of Madaya to assess the extent of malnutrition and evacuate the worst cases, its representative said on Tuesday, Reuters is reporting.
WHO's Damascus representative Elizabeth Roth told Reuters that she is "really alarmed" and that WHO needs to do a "door-to-door assessment" in the town.
Unconfirmed reports of 10 dead in Istanbul.
The Wall Street Journal's Thomas Grove says the blast in Istanbul was likely a suicide bomber.
Casualties have been reported in an explosion in central Istanbul.
From our news desk:
Casualties Reported In Central Istanbul Blast
Reports from Turkey say an explosion has rocked the center of Istanbul, causing some casualties.
The explosion occurred on January 12 in Sultanahmet Square, a major tourist attraction.
Police sealed off the square after the blast.
The Sultanahmet neighborhood is Istanbul's main sightseeing area and includes the Topkapi Palace, Hagia Sophia, and the Blue Mosque.
The blast in Turkey's largest city comes after a series of deadly attacks across the country in past months.
Two suicide bombs in the capital, Ankara, in October killed more than 100 people. Prosecutors said that attack was carried out by Islamic State militants.
Turkey is also waging an assault on the banned Kurdistan Workers' Party, which has staged deadly attacks against members of the security forces in the country's southeast.