UN head Ban Ki-moon says Syria could become a \"regional battleground,\" as fighting continues to rage across the country. A watchdog said dozens were killled in the northern town of Ras al-Ain on Tuesday after clashes between rebels and a Kurdish militia. Speaking on a visit to Cairo, UN Secretary General Ban cautioned that on the ground there was 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,\" he said. He also urged donor countries \"to contribute generously\" to humanitarian programmes inside Syria and help Syrian neighbours which have taken in tens of thousands of refugees. Turkey, which is hosting more than 120,000 Syrian refugees, said it would formally ask its NATO partners for Patriot anti-missile systems to protect its border. Foreign Minister Ahmet Davutoglu said: \"(Patriots) are a precautionary measure, for defence in particular. We will submit the formal request as soon as possible.\" Earlier, Britain formally recognised newly-formed opposition bloc National Coalition as the sole representative of the Syrian people.  Foreign Secretary William 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 Assad\'s regime. Last week, France became the first Western country to recognise the coalition and on Monday the European Union said it \"considers them legitimate representatives of the aspirations of the Syrian people.\"