For the month of April, Massachusetts foreclosure activity remained at levels dramatically below those recorded last year, according to data released this week by the Warren Group, a Boston-based real estate data provider.

However foreclosure petitions, which mark the first step in the foreclosure process in the Bay State, posted their highest number so far this year.

The Warren Group reports that the number of foreclosure petitions statewide dropped almost 51 percent

year-over-year to 1,192 in April. In the three previous months, petitions ranged from 694 to 1,048. April marked the highest number of petitions recorded since September, when there were 2,358 starts.

Through April of this year, 3,727 petitions to foreclose were filed in Massachusetts, down 58.6 percent from the same period in 2010.

“Lenders are still taking a cautious approach to foreclosures, and this is keeping foreclosure statistics at low levels for a while longer,” said Timothy M. Warren Jr., CEO of the Warren Group.

“This brief downturn should not sway us from the reality that the foreclosure crisis is not over, and we are likely to see more activity work its way through the system,” Warren said. “The increase in petitions from March to April shows that foreclosure activity has picked up a bit again, and we are likely to see increases in coming months.”

Foreclosure deeds, which represent completed foreclosures, decreased more than 62 percent last month from April 2010. Advertised auction notices also dropped, down 51.7 percent from a year ago.