The UK's energy price cap is expected to rise to around £2,800 ($3,500) in October, the boss of the country's energy regulator warned on Tuesday, meaning residents will see their gas and electricity bills hike further.

"Gas prices are higher and highly volatile," Jonathan Brearley, head of the UK Office of Gas and Electricity Markets (Ofgem), told MPs, citing the conflict in Ukraine, the BBC reported.

The price cap, which is the maximum price per unit that suppliers can charge customers, is currently at £1,971 ($2,464) and already went up about £700 in April.