The Syrian military is firing ballistic missiles into populated areas where it is battling rebels, killing hundreds of civilians in recent months, Human Rights Watch said in a report today, as rebels battled government troops in the coastal province of Latakia for a second straight day.

The U.S.-based group said Monday it has investigated nine apparent missile attacks that killed at least 215 people, half of them children, between February and July. The most recent attack HRW investigated occurred in the northern province of Aleppo on July 26, killing at least 33 civilians including 17 children.

HRW activists visited the sites of seven of the nine attacks and found no apparent military targets nearby, the group said. Ole Solvang, a senior researcher with HRW, said it's impossible to distinguish between civilians and fighters when firing missiles with wide-ranging destructive effects into densely populated areas.

"Even if there are fighters in the area, you cannot accurately target them and the impact in some of these cases has been devastating to local civilians," Solvang said in a statement.

The HRW called on President Bashar al-Assad to stop indiscriminate attacks.

Government officials could not immediately be reached for comment. The military has repeatedly denied it is targeting civilians during the two-year conflict, saying its troops are fighting "terrorists" hiding in civilian areas.

Sectarian tone in conflict

The Human Rights Watch Report comes as the Britain-based Syrian Observatory for Human Rights said rebels took control of four villages in mountainous terrain near the Mediterranean sea.

Like much of Latakia province, they were populated by Alawites, members of the Shiite offshoot sect to which Assad's family belongs.

Syria's conflict has taken on an increasingly sectarian tone in the last year, pitting predominantly Sunni Muslim rebels against the Alawite-dominated regime.

On Sunday, according to the Observatory, rebels attacked government outposts in the Jabal al-Akrad hills. The group, which relies on reports from activists, said at least 32 government troops and militiamen and at least 19 rebels, including foreign fighters, died in the fighting.

Much of Latakia has been under the firm control of Assad's forces since the beginning of the conflict more than two years ago, but some areas including the Jabal al-Akrad are close to rebel-held areas and have seen fighting.

It was a rare success for the rebels on the battlefield in recent weeks. Assad's forces have been on the offensive since taking the central town of Qusair in June.

Syria's main opposition bloc hailed the rebel advance, and said the Syrian military had used the captured territory to attack rebel-held civilian areas.

More than 100,000 killed in civil war

More than 100,000 people have been killed since the conflict started in March 2011 as largely peaceful protests against Assad's rule. It turned into an armed uprising after opposition supporters took up arms to fight a brutal government crackdown on dissent.

The Assad government claims it is not facing a popular revolt, but a conspiracy by Gulf Arab states and the West seeking to destroy Syria by supplying Islamic extremists with weapons and funds.

In his last public appearance late Sunday, Assad called on the Syrians to unite behind the army's efforts to "defend their homeland."

"There is no solution with terrorism but to strike with an iron fist," Assad was quoted as saying by state news agency SANA. "With this kind of battles that aim at the destruction of the cultural identity and the Syrian national fabric, we either win together as Syrians or lose together."

Assad spoke while taking part in an iftar, the meal that breaks the dawn-to-dusk fast during the Muslim holy month of Ramadan.