Seventeen people were killed and more than 150 injured in two explosions in a crowded Istanbul square late on Sunday night.

Investigators yesterday were trying to determine who was behind the attacks.

But Istanbul Governor Muammer Guler said the blasts may be linked to a Kurdish rebel group. "There appears to be a link with the separatist organization. We are working on that. We hope to get a result at the first opportunity," Guler said.

But the rebel Kurdistan Workers' Party (PKK) rejected the allegation. "The Kurdish freedom movement has nothing to do with this event, this cannot be linked to the PKK," Kurdish rebel leader Zubeyir Aydar was quoted as saying by a pro-Kurdish news agency, Firat.

"We extend our condolences to the families of the victims and to the Turkish people," Aydar said.

The bombs went off in the residential neighborhood of Gungoren in a busy square closed to the traffic where people congregate at night, often bringing their children to have ice cream or sunflower seeds. Two of those killed on Sunday were children.

Prime Minister Recep Tayyip Erdogan canceled a Cabinet meeting yesterday in the capital, Ankara, to travel to Istanbul.

The attack came on the eve of deliberations by Turkey's top court on whether to ban the ruling party for allegedly trying to steer the country towards Islamic rule. There was no evidence of a link or claim of responsibility.

Turkey is home to a variety of militants, including Kurdish rebels and Islamic extremists, and alleged coup plotters with ties to the secular establishment.

Opposition leader Deniz Baykal said security officials told him the type of bombs used were similar to those used in attacks in Ankara and the mostly Kurdish city of Diyarbakir that were blamed on the PKK.

The high level of professionalism in the Istanbul bombings, apparently designed to inflict maximum casualties among civilians, was unsettling.

Authorities said the vast majority of the deaths and injuries occurred when a curious crowd gathered after the first, but much smaller blast.

"First, they exploded a percussion bomb to grab attention. Then, 10 minutes later, in another trash-can, they exploded a fragmentation bomb," said Hayati Yazici, deputy prime minister.

The Cihan news agency said the second bomb consisted of the same plastic explosive used in a May 2007 suicide attack in Ankara that killed seven people.

Questions:

1. How many people were injured in Sunday’s bomb attacks?

2. According to the article which organisation is being blamed for the attack?

3. How many minutes past before the second bomb exploded?

Answers:

1. 150.

2. Kurdistan Workers' Party (PKK).

3. 10 minutes.