Greek coastguard denies claims refugee boat capsized after tow rope attached

UN calls for urgent action to prevent further tragedies as police believe up to 500 people remain missing

Greek authorities have rejected claims that a fishing boat that sank in the Mediterranean this week with the loss of potentially hundreds of lives capsized after the coastguard attempted to tow it, as the UN called for urgent action to prevent further tragedies.

Authorities have confirmed 78 deaths and said 104 survivors - mostly from Syria, Egypt and Pakistan - had been brought ashore, but police believe as many as 500 are missing. Witnesses have reported that up to 100 children were in the ship's hold.