Britain formally recognised a newly-formed opposition bloc as the sole representative of the Syrian people on Tuesday, as the chief of the UN said he feared Syria could become a \"regional battleground.\" Britain\'s recognition of the opposition National Coalition came as fighting raged across Syrian flashpoints, including in the northern town of Ras al-Ain where a watchdog said dozens died in clashes between rebels and a Kurdish militia. Turkish Foreign Minister Ahmet Davutoglu said meanwhile that NATO member Ankara, a sharp critic of President Bashar al-Assad\'s regime, would formally ask the alliance for Patriot missiles to protect its border with Syria. In announcing Britain\'s recognition of the National Coalition formed in Doha on November 11, Foreign Secretary William Hague told parliament he took the decision after he met leaders of the bloc in London on Friday and they assured him that they have backing inside Syria and would respect human rights. Hague said he has asked the group to appoint a political representative to Britain and he announced an increase in aid and support for the coalition as it battles the regime of Syrian President Bashar al-Assad. The move comes one week after France became the first Western country to recognise the coalition and after the European Union on Monday said it \"considers them legitimate representatives of the aspirations of the Syrian people.\" But even as momentum for recognising a credible opposition to Assad gathered steam, UN Secretary General Ban Ki-moon, on a visit to Cairo, cautioned that on the ground there was a potential for the conflict to spin out of control. \"We are deeply concerned about the continued militarisation of the conflict, horrendous violations of human rights and the risk of Syria turning into a regional battleground as the violence intensifies,\" Ban told reporters. He also appealed to countries \"to generously contribute more to our humanitarian programmes inside Syria and in the region and to assist Syria\'s neighbours in dealing with the refugee crisis.\" Turkey, which is already hosting more than 120,000 Syrian refugees, said it would formally ask NATO for Patriot missiles to protect its border. \"(Patriots) are a precautionary measure, for defence in particular,\" Ahmet Davutoglu, the foreign minister of the NATO-member state told reporters before he left Ankara for Gaza. \"We will submit the formal request as soon as possible.\" Over the past several months, Turkey has steadily reinforced its border defences, notably after five of its nationals were killed by artillery fire from Syria in October. Rebel intelligence service ------------------------- Syrian rebels, meanwhile, announced Tuesday the creation of a security service to \"defend the Syrian revolution\" in a country that has been awash with feared intelligence agencies for the past five decades. Its objective is \"to be a powerful security shield to protect the sons of the revolution from attacks, arrests and killings,\" and to hunt down members of the opposition who have committed abuses, according to a video statement by rebels. On the ground, rebel battalions attacked the Sheikh Suleiman air defence battalion west of Aleppo city, the Syrian Observatory for Human Rights said. The clashes came less than two days after rebels, armed with at least five tanks according to a military source, took full control of the sprawling Base 46 in the same province. Fresh fighting between Kurdish militiamen and rebels erupted in Ras al-Ain on the Turkish border, previously a safe area which insurgents captured last week.  The casualties over the past day included four Kurdish fighters, a local Kurdish official, and 24 members of the Islamist Al-Nusra Front and Gharba al-Sham rebel battalions, Observatory director Rami Abdel Rahman told AFP. The Kurdish fighters are members of the People\'s Defence Units, the armed wing of the Democratic Union Party (PYD) which is linked to Turkey\'s rebel Kurdistan Workers\' Party (PKK) and accused by rebels of collusion with the regime. The clashes erupted after Kurds protested the entry of rebels into their area, which they say provides safe haven to thousands of refugees. Violence also broke out in the capital where state media reported that two mortars hit the ministry of information building. The Observatory puts the death toll in more than 20 months of conflict at more than 39,000.