Turkey's main Kurdish party on Saturday accused the government of turning a blind eye to—if not outright supporting—ISIS militants within its borders after suicide bombers attacked the town of Kobani along its southern border with Syria. The Turkish government vehemently denies the claims.

ISIS "used to attack the town from three sides," said the UK-based Syrian Observatory for Human Rights and Nawaf Khalil, a spokesman for Syria's Kurdish Democratic Union Party, in a statement. "Today, they are attacking from four sides," noting the addition of Turkey.

Mustafa Bali, a Kobani-based activist, told the Associated Press that ISIS fighters have taken positions in the grain silos on the Turkish side of the border and to coordinate and launch attacks along the border near the crossing point. "It is now clear that Turkey is openly cooperating with Daesh," said Bali, using the Arabic acronym ISIS.

"As we have been pointing out for months, this once more proves that Islamic State is being supported (from within Turkey)," Turkey's pro-Kurdish HDP party said in a statement.

The accusations come at a time when Pope Francis is visiting Turkey. During comments on Friday, he condemned the "barbaric violence" of ISIS and urged Turkish President Tayyip Erdogan to take lawful steps—and not just militaristic ones—to defeat extremism.