Context :

Aims : The study of the observational properties of uncommonly long bursts from low luminosity sources is important when investigating the transition from a hydrogen - rich bursting regime to a pure helium regime and from helium burning to carbon burning as predicted by current burst theories .
On a few occasions X-ray bursts have been observed with extended decay times up to several tens of minutes , intermediate between usual type I X-ray bursts and so-called superbursts .

Methods : IGRÂ J17254-3257Â is a recently discovered X-ray burster of which only two bursts have been recorded : an ordinary short type I X-ray burst , and a 15Â min long burst .
The properties of the X-ray bursts observed from IGRÂ J17254-3257Â are investigated .
The broad-band spectrum of the persistent emission in the 0.3–100 keV energy band is studied using contemporaneous INTEGRAL and XMM-Newton data .

Results : A refined position of IGRÂ J17254-3257Â is given and an upper limit to its distance is estimated to about 14.5 kpc .
The persistent bolometric flux of 1.1 \times 10 ^ { -10 } erg cm ^ { -2 } s ^ { -1 } corresponds , at the canonical distance of 8Â kpc , to L _ { pers } \approx~ { } 8.4 \times 10 ^ { 35 } erg s ^ { -1 } between 0.1–100 keV , which translates to a mean accretion rate of about 7 \times 10 ^ { -11 } M _ { \odot } yr ^ { -1 } .

Conclusions : The low X-ray persistent luminosity of IGRÂ J17254-3257Â seems to indicate the source may be in a state of low accretion rate usually associated with a hard spectrum in the X-ray range .
The nuclear burning regime may be intermediate between pure He and mixed H/He burning .
The long burst is the result of the accumulation of a thick He layer , while the short one is a prematurate H-triggered He burning burst at a slightly lower accretion rate .