United Nations war crimes investigators on Tuesday said they were investigating reports that chemical weapons were being used in rebel-held zones in war-ravaged Syria.

President Recep Tayyip Erdogan on Tuesday warned the United States to withdraw any American forces from the Syrian town of Manbij, vowing Turkish troops would expand a cross-border military operation to the key strategic hub.

Fresh regime strikes on a besieged rebel-held enclave near Damascus killed 47 civilians on Tuesday despite mounting Western pressure on Syrian President Bashar al-Assad.

The bloodshed came a day after another 31 civilians were killed in Eastern Ghouta and as the United Nations pleaded for a truce in the seven-year-old war to allow for aid deliveries.

The United Nations in Syria appealed on Tuesday for a one-month truce in the conflict to allow aid to reach hundreds of thousands of civilians in urgent need of assistance.

Yemeni government forces have retaken a key southwestern crossroads town from Shiite rebels as they press an offensive up the Red Sea coast, military and medical sources said on Tuesday.

A Turkish soldier was killed and six people wounded in rocket and mortar attacks on the Turkish military in Syria's northwestern province of Idlib, the army said Tuesday.

A Palestinian man wanted over the murder last month of a rabbi near a Jewish settlement in the West Bank has been killed, Israel's Shin Bet security service said Tuesday.

The United States accused Russia on Monday of delaying the adoption of a U.N. Security Council condemnation of reported chlorine gas attacks in Syria that left many injured in recent days, including children.

Human trafficking is on the rise in Libya, according to a report by a U.N. panel of experts which found that Libyan forces may be helping rebel groups tighten their control of smuggling routes.

The confidential report sent to the U.N. Security Council also said the Islamic State group is seeking to join migrant smugglers in southern Libya after it was pushed out of Sirte in 2016.

The Polisario Front which seeks independence for Western Sahara said Monday it is ready for direct negotiations with Morocco on the future of the disputed territory.