Airspace over the Republic of Ireland is due to be reopened later Tuesday following a six-hour closure because of an ash cloud from an Icelandic volcano, DPA reported.
The Irish Aviation Authority (IAA) gave the go-ahead for flights to resume from 1200 GMT, saying that the situation would be "reviewed as the week goes on."
Britain's Civil Aviation Authoriry (CAA) said it would make a decision on whether to lift restrictions on airports in Northern Ireland, including Belfast, later Tuesday.
"Our decision to close earlier today was based solely on the safety risks to crews and passengers as a result of the drift south of the volcanic ash cloud caused by the north-easterly winds, an IAA spokesman said.
"The situation will be reviewed as the week goes on. Winds are forecast to continue coming from a northerly direction for the next few days and this could lead to further problems."
Restrictions on some small airports in Scotland's Outer Hebrides remain in force.