Two bomb blasts killed 13 people and injured 70 others late on Sunday when two bombs exploded in a busy shopping district in Istanbul, the city's governor said. The first bomb created a small blast in a telephone booth in the busy shopping and residential district of Gungoren on the European bank of the Turkish city. About 10 minutes later, a second, stronger explosion a few meters away booby-trapped people who began to gather at the site to help those injured in the first blast, the Turkish NTV television station quoted Governor Muammer Guler. The governor said the bombs were placed in trash bins and that it was not a suicide bombing. Local television stations had initially reported that the blasts were caused by a gas leak. Guler downplayed speculation that rebels of the outlawed Kurdistan Workers' Party (PKK) could be responsible for the blasts, saying it was too early to say who was to blame, but saying “there is no doubt that this is a terror attack.” He said officials would study the images filmed by surveillance cameras near the scene of the attacks. In the past, numerous attacks in Istanbul have been blamed on the PKK, considered a terrorist group by Turkey and Western powers, which has been fighting since 1984 for independence for the Kurdish-majority southeast region. The images broadcast by NTV showed scenes of panic, with people covered in blood and disoriented as they ran from the area of the blasts, littered with debris and shattered glass. Teams of firefighters and emergency workers were dispatched to the scene and police established a security perimeter. “We received nearly 30 very heavily wounded people,” said Abdullah Toker, a manager at Gungoren Kolon Hospital. “Tens of people were scattered around. People's heads, arms, were flying in the air,” said one eyewitness. “The first explosion was not very strong,” said Huseyin Senturk, who owns a shoe shop in the area. “Several people came to see what was going on. That's when the second explosion occurred and it injured many onlookers.” The second explosion could be heard two kilometers away, according to an Associated Press reporter who arrived to the scene shortly after the blasts. Nurettin Kapucu, a doctor at a nearby hospital, said some 25 people were being treated there. Three of them were in serious condition. Police sealed off the two separate locations at the square where the explosions occurred. The square is off limits to traffic and is an area where people congregate at nighttime. “The fact that there was a crowd in the area has increased the number of casualties,” Guler said. Bomb squads in white overalls could be seen inspecting the scene.