ANTAKYA, Turkey -- Despite the international outcry over recent massacres allegedly committed by backers of President Bashar Assad, statistics compiled by human rights activists show that violence in Syria has dropped since a United Nations peace plan went into effect in April and is down sharply from its peak in March.

One measure of violence, however, seems to have increased appreciably: More Syrian soldiers were killed in clashes with rebels in May than in any month since the 14-month-old uprising began.

There were also reports that arrests by Syrian security forces have increased, a violation of the U.N. plan that appears to be a major factor in the violence.

“Every day the Free Syrian Army is becoming stronger,” said Alaa Kaikooni, a fighter who referred to the rebels by the name for most of the loosely organized groups that have taken up arms against Assad.

Reliable statistics on violence in Syria are difficult to come by. There are no neutral observers collecting information there, and any death toll is suspect. The United Nations stopped trying to tabulate deaths at the beginning of the year because of the difficulties involved in verifying the numbers, and the general trend is hard to discern amid daily reports of horrific mass killings and loud denunciations from U.S. and other international officials.

But a new report listing the names of the dead and the dates on which they died, compiled by the London-based Syrian Network for Human Rights, for the first time provides a baseline for determining whether Syria is become less or more violent.

That report, which lists more than 14,000 names over 296 pages, indicates that since the U.N. peace plan went into effect in April, violence is off 36 percent from its peak and has dropped in each of the months that the plan has been in place.

Those numbers are still incredibly high – the Syrian Network for Human Rights recorded 1,344 deaths in May, including 55 noted after the report was posted on the network’s website Tuesday. Still, that’s far fewer than the 2,101 deaths the network tracked in March or the 1,610 it recorded in April. It’s lower than any month so far this year – with the exception of January, when the network reported that 1,179 people were killed – and below the monthly average of 1,616 deaths from January to May.

.Of the 14,093 people whose names are listed in the report, 8,082 died in the first five months of this year, testament to the quickening pace of violence as Assad’s opponents picked up weapons and began to attack army patrols. In contrast, 6,011 people were listed as having been killed from March 18, 2011, to the end of last year.

Even those numbers, however, understate the number of Syrians who’ve lost their lives since crowds of peaceful demonstrators began demanding change, only to be met with live gunfire by government security forces. Missing, for the most part, are the hundreds of police officers and soldiers who the Syrian government claims have been killed in rebel attacks.

According to news articles posted on the government news agency’s website, 953 police officers and soldiers have died since March 11. Of those, 404 or 42 percent, were killed in May alone.

There was no easy explanation for why the Syrian security death toll was up while the number of civilian dead appears to have declined. Last month, in a rare interview, on-duty Syrian soldiers told a McClatchy reporter that rebel forces targeted their checkpoints daily, and rebel commanders often boast of attacks on Syrian military outposts.