Ten Protestant men were killed by republicans at Kingsmills, Co Armagh, the day after six men from two Catholic families were murdered by loyalists.

An event is being held at the site where 10 Protestant workmen were killed on January 5 1976.

The ombudsman detailed failures including several instances of police planning to arrest suspects but not following through.

Ten Protestant workmen were shot dead by the IRA outside the village of Kingsmill in 1976 in one of the most notorious incidents of the Troubles.

Ten Protestant workmen were shot dead in the sectarian attack by the IRA in Co Armagh in 1976.