Did You Know
Did You Know
Four people have been arrested in connection with a car bomb attack on a police bus in Istanbul which killed 11 people, seven of them officers.
"Seven police and four citizens lost their lives," the city's governor, Vasip Sahin, said at the scene in the Beyazit district.
Thirty-six others were injured - at least three of them were in a serious condition.
Turkey's state-run Anadolu news agency said the four suspects were being questioned at Istanbul's main police headquarters.
The private Dogan news agency claimed they had hired the car used in the attack.
The explosion took place close to the Vezneciler metro station, which was closed as a security precaution.
It was also near an Istanbul University building, forcing officials to cancel exams.
The force of the blast caused the police bus - carrying rapid-response officers - to overturn.
Nearby buildings were damaged, while several cars were wrecked.
Television footage showed windows blown out and debris littering the floor of the 16th-century Sehzade Mosque.
"There was a loud bang, we thought it was lightning but right at that second the windows of the shop came down," said a local shopkeeper, Cevher.
Goods toppled from his shelves. "It was extremely scary," he said.
It is the fourth major bombing in Turkey's biggest city this year - two targeting security forces and the other two aimed at tourists.
Windows were blown out by the force of the blast
The violence has led to a sharp dip in tourism, damaging the economy.
According to official figures, 1.75 million people visited Turkey in April, more than 28% down on April 2015.
Mr Sahin did not comment on who may have been behind the attack, but the Kurdistan Workers' Party, or PKK, has been targeting police and military personnel with bombs since July, after a fragile peace process between it and the government collapsed.
It happened not far from some of Istanbul's main historical sights
Turkey's president, Recep Tayyip Erdogan, visited some of the wounded at Haseki hospital.
"These (attacks) are being carried out against people whose duty it is to ensure the security of our people," he said.
"These cannot be pardoned or forgiven. We shall continue our fight against terrorists tirelessly until the end."
He also hinted that he believed the attack was carried out by the PKK.
For the group to target major cities such as Istanbul "is nothing new", he said.
In a TV interview, foreign minister Mevlut Cavusoglu also condemned the attack, saying: "They are cold-heartedly exploding bombs on a Ramadan day."