London: Amnesty International on Wednesday accused the Syrian regime of committing crimes against humanity during a deadly crackdown over a pro-democracy protest in a border town.

The London-based rights group urged the United Nations to take action over the assault by the security forces and army on Tall Kalakh in May, amid the protests against President Bashar al-Assad's rule that have swept the country.

In a new report, Amnesty made allegations of torture, deaths in custody and arbitrary detention during the security sweep that lasted several days in the town near the Lebanese border.

"The accounts we have heard from witnesses to events in Tall Kalakh paint a deeply disturbing picture of systematic, targeted abuses to crush dissent," said Philip Luther, Amnesty's Middle East and North Africa Deputy Director.

Security forces and the army entered the town on May 14 after an anti-government protest, according to the report, which is based on interviews with more than 50 people that Amnesty talked to by phone and in Lebanon.

The rights group has not been allowed to enter Syria. Scores of male residents were rounded up and most of those detained were tortured, with at least nine people dying in custody, according to accounts given to Amnesty.

"Amnesty International considers that crimes committed in Tall Kalakh amount to crimes against humanity," said a statement from the group.

Luther added, "Most of the crimes described in this report would fall within the jurisdiction of the International Criminal Court. But the UN Security Council must first refer the situation in Syria to the court's prosecutor."

The anti-government protests against Assad's rule began in mid-March, inspired by revolts in other countries in the Arab world.

Protesters have defied a deadly crackdown by the authorities to push on with demonstrations in many parts of the country. Rights groups say that more than 1,300 civilians have been killed since the protests started.