More than a thousand Russian troops are operating inside Ukrainian territory according to NATO, who released satellite images showing forces with heavy weaponry.

"Over the past two weeks we have noted a significant escalation in both the level and sophistication of Russia's military interference in Ukraine," Dutch Brigadier-General Nico Tak, head of NATO's crisis management centre said reports Reuters.

"We assess well over 1,000 Russian troops are now operating inside Ukraine," he said, referring to Russia's actions as "incursions" rather than an invasion. "They are supporting separatists (and) fighting with them."

"We have also detected large quantities of advanced weapons, including air defence systems, artillery, tanks and armoured personnel carriers being transferred to separatist forces in eastern Ukraine," he said.

The UN Security Council met in an emergency session, and NATO and EU leaders said they will will consider a response on Friday, but Russia denied that its troops where in Ukraine.

Ukrainian President Peter Poroschenko also said that Russians were supporting pro-Moscow rebels, who captured Novoazovsk and other parts of southeast Ukraine.

Members of the UN Disengagement Observer Force (Undof) in Syria’s Golan Heights are being held by an “armed group” according to the UN.

A UN spokesperson said the 43 peacekeepers were detained "during a period of increased fighting beginning yesterday between armed elements and Syrian Arab Armed Forces within the area of separation".

Three people have been killed after a United Nations helicopter crashed in South Sudan, with unconfirmed reports that it had been shot down.

The helicopter crew were all Russian citizens. The helicopter’s owners, Russian airline UTair, stated that,

Rebels in South Sudan have denied shooting down a UN helicopter, which crashed on Tuesday, killing 3 and injuring one of those on board.

The rebel SPLM dismissed the claims made by the South Sudanese army as government propaganda.

"The SPLM/SPLA [in Opposition] would like to take this opportunity to refute these malicious allegations levelled by the propaganda machine of the Government of the Republic of South Sudan (GRSS)," said the statement, which bore the signature of Mabior Garang de Mabior, the chairperson of the committee for information and public relations.

"The area in which the plane was reportedly shot down is government-held territory, if indeed the aircraft was shot down. It is unfortunate that the GRSS propaganda machine is trying to capitalise on this unfortunate event to score political points,"

According to the Sudan Tribune, rebel brigadier-general Lul Ruai Koang pledged to assist any investigations.

The UN has accused the Syrian government and rebels opposed to it of committing war crimes in Syria.

A report released by the Independent International Commission of Inquiry on the Syrian Arab Republic details abuses by Islamic State and other rebel groups fighting Bashar al-Assad’s regime.

The government is thought to have conducted chemical attacks eight times this year alone and used barrel bombs on civilian areas.

"In some instances, there is clear evidence that civilian gatherings were deliberately targeted" by government forces, the investigators said.

"In government prisons, detainees were subjected to horrific torture and sexual assault."

A long-term truce has been agreed between Israelis and Palestinians, after intense negotiations, brokered by Egypt.

Palestinian and Egyptian officials announced the end to 7-weeks of fighting, which killed over 2,200 people, mostly Palestinian civilians.

Hamas spokesperson Sami Abu Zuhri said in a statement, “An agreement has been reached between the two sides and we are awaiting the announcement from Cairo to determine the zero hour for implementation.”

Ismail Haniya, the former Hamas prime minister in Gaza, told Al Aqsa television that “we are at the doors of political understandings that will crown our people’s steadfastness and the performance of our armed resistance.”

President Barack Obama has approved surveillance flights over Syria to gain information on Islamic State militants.

Nearly 500 Nigerian soldiers have fled into Cameroon after severe clashes with Boko Haram fighters, according to Cameroon’s army.

Spokesman Lt Col Didier Badjek told the BBC that the soldiers have been disarmed and are being accommodated in schools in Maroua, around 80km from the Nigerian border.

Ukrainian troops have engaged in clashes with Russian troops which crossed the border in the southeast of the country.

Ukrainian military spokesperson Andriy Lysenko said Russian military vehicles with the insignia of the self-proclaimed Donetsk People’s Republic “violated the state border of Ukraine” in the southern part of Donetsk region.

Lysenko said at least 10 tanks, two armored vehicles and two trucks from Russia crossed into the country on Monday soon after which they engaged in clashes with a Ukrainian military border unit.