ANKARA, Turkey (AP) — Turkey came under scrutiny on Tuesday for alleged human rights violations committed by security forces against Kurds in the southeast and Syrian refugees trying to enter the country, with two organizations calling for investigations.

Human Rights Watch claimed that Turkish border guards have in the past two months killed five Syrians who were trying to cross into Turkey, and called on the country to investigate the reported use of excessive force by soldiers.

Separately, the U.N. human rights chief urged Turkey to allow investigators to probe allegations of violations committed by Turkish security forces in their campaign against Kurdish rebels.

New York-based Human Rights Watch accused border guards of shooting and beating asylum-seekers and at least one smuggler. It said that five refugees — including a child — were killed and 14 others were wounded in March and April.

A Turkish Interior Ministry official denied that the incidents cited by Human Rights Watch had occurred and insisted that the country, which is home to 2.7 million Syrian refugees, does not shoot at asylum-seekers. The official cannot be named because of regulations that bar civil servants from speaking to journalists without authorization.

Human Rights Watch also urged Turkey to reopen its border to all Syrian asylum-seekers, claiming that Turkish border guards blocked thousands of fleeing displaced Syrians after their camps near the Turkish border had been attacked on April 13 and 15.

The report could not independently be verified by The Associated Press.

Turkey maintains that it has an open-door policy toward migrants, although new arrivals are rare.

"Firing at traumatized men, women, and children fleeing fighting and indiscriminate warfare is truly appalling," said Gerry Simpson, senior refugee researcher at Human Rights Watch.

The U.N. human rights chief, Zeid Raad al-Hussein, said he has received reports of unarmed civilians, including women and children, being deliberately shot by snipers or from military vehicles in the course of security operations in southeastern Turkey. Those operations focused on mainly Kurdish towns where militants and youths linked to the outlawed Kurdistan Workers' Party are active.

"While Turkey has a duty to protect its population from acts of violence, it is essential that the authorities respect human rights at all times while undertaking security or counter-terrorism operations," Zeid said.

The Turkish government had not responded positively to U.N requests to visit the region and collect information, he added.

The U.N. wants to investigate reports that more than 100 people were burned to death in the town of Cizre while sheltering in basements surrounded by security forces, who are also accused of carrying out arbitrary arrests, torture and other types of violence.

The U.N. also wants to investigate allegations that security forces used massive and disproportionate forces contributing to the destruction of communal infrastructure and private property, as well as mass displacement of locals.

Zeid noted that many other districts in the southeast remain largely sealed off due to the high security presence.

"In 2016, to have such a lack of information about what is happening in such a large and geographically accessible area is both extraordinary and deeply worrying," he said. "This black-out simply fuels suspicions about what has been going on. I therefore renew my call for access for UN staff and other impartial observers and investigators, including civil society organizations and journalists."

Soguel reported from Istanbul, Turkey. Jamey Keaten in Geneva, Switzerland, also contributed.