Calls were growing last night for the screening of young people for health problems after the sudden deaths of four schoolboys in less than a week.

A post-mortem examination takes place today to confirm the cause of death of Patrick Devlin (13), who collapsed at a GAA pitch in Ardobe in Co Tyrone on Saturday.

The tragedy happened as mourners gathered in Drumquin in Co Tyrone for the funeral of 10-year-old Patrick Breen, who died in similar circumstances on Tuesday evening. 

Both boys died despite frantic efforts to revive them, including the use of a defibrillator. 

The harrowing scenes were mirrored in Co Westmeath last week, where two 16-year-olds died suddenly. 

Zeeshan Muhammed collapsed while playing football in a school yard in Athlone on Friday - the same day as the funeral of Tony Parker, who had died minutes before a PE class in Moate on Tuesday. 

Post-mortem examination results have not yet been released. 

The charity Cardiac Risk in the Young estimates that at least eight young people die each week in Britain and Northern Ireland from undiagnosed heart conditions. 

The issue was highlighted across Ireland following the deaths of Tyrone GAA captain Cormac McAnallen and young rugby star John McCall in 2004. 

A study in Italy last year found that screening for heart defects has saved lives and proved cost-effective. 

Mr McAnallen's father Brendan said health checks should be compulsory. 

"I believe that every young person should be screened because every person plays sports, not only athletes but indeed children," he said. 

The GAA's Ulster Council secretary Danny Murphy expressed "disbelief" at the latest death and said screening for children of school-going age should be looked at. 

Deputy First Minister Martin McGuinness also expressed shock at the deaths. 

"It is proper that we look closely at the health and safety of our young children participating in sports to see if there is more than can be done to help sporting organisations monitor the health of our young people and respond quickly if any problems emerge," Mr McGuiness said. 

Meanwhile double All-Ireland medial winner James McCartan jnr was discharged from hospital yesterday afternoon after collapsing on the sidelines during a club match in Newry.