SURUC • Turkey has stepped up security on its border with Syria after a suicide bombing blamed on Islamic State in Iraq and Syria (ISIS) extremists killed 31 people and raised fears of a spillover of the Syrian conflict onto its territory.

Monday's attack in Suruc, a town on the border with Syria, was one of the deadliest in Turkey in recent years and the first time the government has directly accused ISIS of an act of terror on Turkish soil.

Newspaper front pages yesterday showed photos of the mutilated corpses of pro-Kurdish activists.

"Security on our borders will continue to be increased," Prime Minister Ahmet Davutoglu said, adding: "This attack targets us all."

He urged all political parties to demonstrate unity, and vowed to bring the perpetrators to justice.

The blast ripped through a cultural centre in Suruc hosting about 300 socialist youth activists. Most of the 31 dead and about 100 wounded were university students.

Hundreds of pro-Kurdish activists took to the streets on Monday night to protest against the attack and government policy on Syria, with police in Istanbul using water cannon to disperse the rally.

Dozens of people were killed last October in nationwide protests against the government's perceived lack of support for Kurds battling ISIS militants.

ISIS has not claimed the attack.

Turkey has long been accused by its Western partners of not doing enough to halt the rise of ISIS and even colluding with the group, allegations it vehemently denies.

But Ankara has of late appeared to take a harder line, rounding up dozens of suspected ISIS members in Istanbul and other cities.

Nato member Turkey's main aim in the Syria conflict has been the ousting of President Bashar al-Assad and containment of pro-Kurdish groups.

AGENCE FRANCE-PRESSE