At least 10 people died and dozens were injured when an explosion rocked Philippine President Rodrigo Duterte's home city of Davao on Friday night, authorities said.

The explosion occurred just before 11:00 pm (1500 GMT) at a bustling market and close to one of Davao's top hotels, city spokeswoman Catherine dela Rey told AFP.
"There was an explosion but, as to what caused it, it is still under investigation," dela Rey said.
"Ten people died on the spot, at least 30 injured."
Davao is the biggest city in the southern Philippines, with a population of about two million people. It is about 1,500 kilometres (930 miles) from the capital of Manila.
Duterte had been mayor of Davao for most of the past two decades, before winning national elections in a landslide this year and being sworn in as president on June 30.
Islamic militants and communist rebels have carried out deadly attacks in Davao, however authorities stressed it was too early to determine the cause of Friday's blast.
"Right now, we cannot yet give definite answer to questions as to who is behind this as we are also trying to determine what really exploded," the president's son and Davao vice mayor, Paolo Duterte, said in a statement.
"Let us pray for the victims of this unfortunate incident, especially for those who died. Let us pray for those who are being treated in different hospitals and pray for their quick recovery."
The vice mayor confirmed there were "at least" 10 people who died.
He later told AFP that the president was in Davao on Friday night, but was safe.
"He is at the Davao police office with the presidential staff undergoing a briefing," the vice mayor said.
The explosion killed people dining at the night market.
The bodies of at least two victims were lying amid broken plastic tables and chairs, according to an AFP photographer at the scene.
The site of the blast was about 100 metres (yards) from the city's premier hotel, the Marco Polo, and one of Davao's main universities.
The hotel, popular with tourists and business people, was not impacted.

Violence-plagued region

Davao is part of the southern region of Mindanao, where Islamic militants have waged a decades-long separatist insurgency that has claimed more than 120,000 lives.
Communist rebels, who have been waging an armed struggle since 1968, also maintain a presence in rural areas neighbouring Davao.
Duterte became well known for bringing relative peace and order to Davao with hardline security policies, while also brokering local deals with Muslim and communist rebels.
However in 2003 a bomb attack blamed on Muslim rebels at Davao airport killed more than 20 people.
As president, Duterte quickly launched peace talks with the communists, who last week agreed to an indefinite ceasefire.
Duterte has also in recent weeks pursued peace talks with the two main Muslim rebel groups. Its leaders have said they want to broker a lasting peace.
However Duterte has ordered a military offensive against the Abu Sayyaf, a small but extremely dangerous group of militants that has declared allegiance to Islamic State and vowed to continue fighting.
Fifteen soldiers died on Monday in clashes with the Abu Sayyaf on Jolo island, one of the Abu Sayyaf's main strongholds about 900 kilometres from Davao.