Palestinian security forces were concerned Friday morning over the likelihood of violent riots after two teens died Thursday during Nakba Day demonstrations outside Ofer prison near Ramallah, Israel Radio reported.

They were especially worried that the riots could cause friction with IDF forces after Friday prayers.

In addition, the Palestinian Authority declared a national day of mourning Friday in order to allow mass participation in the funeral of the two slain youths.

Unconfirmed reports named the two as Nadem Syam, 17, and Mohamad Odeh, 15. At least three others were injured in the skirmish.

Palestinians said the two had been killed by live ammunition, but Border Police sources insisted troops had only used rubber-coated bullets. The IDF said it was investigating the incident.

Nakba (Catastrophe) Day is observed by Palestinians and their supporters to commemorate their displacement following the establishment of the State of Israel.

A senior Palestinian source warned Thursday that security coordination between Israel and the Palestinian Authority is on the verge of collapse following the fatal clashes. The source, in a conversation with The Times of Israel, said that recent, “dangerous” developments on the ground — notably the killing of two Palestinians in Nakba Day demonstrations earlier in the day — has already led to heavy pressure on the Palestinian leadership to immediately sever ties with Israel’s security apparatuses.

The source said that there was coordination between the two sides ahead of the Thursday demonstrations, but that wasn’t enough to prevent the fatalities. He added that, during discussions with Israeli defense officials in the wake of the incident, the PA was assured that an investigation would be launched into what caused the fatalities and whether soldiers had fired live ammunition.

But even if they didn’t die of live fire, the source said, Fatah and other organizations were demanding that Palestinian defense officials cease coordination with Israel.

“We don’t want an escalation,” he said. “But understand that the situation on the ground is in the brink of exploding.

“We can act to calm the [people’s] sentiments, but it only takes one bullet to raise these feelings again,” he continued, noting that the PA has been organizing meetings to address continued security coordination with Israel.

“We aren’t the South Lebanon Army,” he said, a reference to the militia group Israel once used as a proxy in southern Lebanon against the PLO and Hezbollah. “You must do something here in order to stabilize the situation. [There is] ongoing construction in the settlements, a refusal to freeze construction, and continued mistreatment of Palestinians.

“There is now a hunger strike among the prisoners and the whole situation is very volatile,” continued the source. “We say to you, if conditions continue like this, we will pass over to you the mechanisms [of control] and you will have to deal with the situation.”

Sources in the IDF and defense establishment refused to comment directly on the situation, although they warned that stopping security cooperation could damage the Palestinian side and the economic situation of West Bank residents. The Israeli sources lauded the continued security coordination, since, they said, it serves the interests of both sides.

Avi Issacharoff and Times of Israel staff contributed to this report.