The anticipated growth in the iron ore and coal sectors are pushing the Reserve Bank of Australia to increase interest rates, according to the minutes of the central bank's board meeting in April showed.

The better than expected performances in the commodities industry might trigger the RBA to immediately increase rates.

The RBA minutes said, "The fact that the prospective rise in the terms of trade was now likely to be noticeably stronger than had been expected was a factor suggesting that it might be prudent not to delay adjustment."

According to the central bank, the economy is seen to further strengthen this year, boosted by the rising commodity prices, which in turn would benefit export incomes and require the return of the interest rates to average levels.

The RBA sees the lending rates as "still a little below average," and "members expected that they would probably need to rise further in the period ahead."

The RBA said that with growth forecast in the domestic economy showing a positive trend this year and the inflation seen to hover around 2.5%, which is consistent with government medium-target, the public should expect interest rates to be adjusted to average levels.

However, the minutes are silent when the interest rates hike would be forthcoming, although it said that a 25-basis-point hike would be introduced in the coming months before average levels are fully restored.

Rob Henderson, head of Australian economics at the National Australia Bank, said he expects the RBA to adjust the economic outlook in May which could pave the way for raising interest rates to above normal average.

Henderson said that that could mean the cash-rate target is raised to 5.25% by the end of the year, adding there is growing upside risk to that forecast.