NEW YORK - Syrian security forces responded to a large peaceful protest on July 1, 2011, in Syria's central city of Hama with a series of deadly raids, killing at least 16 people in the last 48 hours, Human Rights Watch said today. Security forces and pro-government armed groups, known locally as shabiha, raided homes, opening fire several times, and set up checkpoints encircling Hama, Syria's fourth-largest city.

"Hama is the latest city to fall victim to President Bashar al-Asad's security forces despite his promises that his government would tolerate peaceful protests," said Sarah Leah Whitson, Middle East director at Human Rights Watch. "Security forces have responded to protests with the brutality that's become familiar over the past several months."

Security forces had been largely absent from Hama, a city of 800,000, since June 3, when they opened fire on anti-government protesters, killing at least 60 people, according to media reports. In the following weeks, Hama residents took to the streets for regular protests that participants and media reports consistently reported as peaceful.

The marches culminated in a massive demonstration in al-Assi square on July 1, which drew tens of thousands of protesters - hundreds of thousands by some estimates. Syrian activists hailed it as the largest protest in Syria since the uprising began in mid-March. The protest was peaceful and unimpeded by government forces, according to witnesses, media reports, and videos reviewed by Human Rights Watch.

The next day, however, President al-Asad fired the governor of Hama, Ahmad Khaled Abdel Aziz, and security forces began a campaign of arrests, local residents and human rights activists told Human Rights Watch. A human rights lawyer, Razan Zeitouneh, told Human Rights Watch that security forces entered the outskirts of the city on July 2 and began arresting people, prompting residents to set tires on fire to prevent security forces from entering their streets. One resident described his neighborhood's response:

We had a system prepared for when the security forces came to arrest people. When we saw them coming, we would bang pots and pans to alert everyone else so the young men in the neighborhood could leave their homes and escape. After a few hours, security forces caught on to the system, so they started throwing teargas and stun grenades so people would be too scared to leave their homes and run away. Security forces then arrest people in bulk and load them into big cars; we don't know where they're taking them. They're targeting men between 10 and 45 years old.

The following day, in the early hours of July 3, security forces deployed in large numbers in the city, witnesses told Human Rights Watch, setting up checkpoints at the city entrances at 4 a.m. One resident said he heard gunfire starting at 2 a.m., then saw the military deploy at 5 a.m.

Residents told Human Rights Watch that arrests subsequently took place in the Hama neighborhoods of `Ain Louza, Gharab al-Mashtal, Janoub al-Mal`ab, al-Jaraajmah, al-Gharayah, al-Hadr, and al-`Alaliyat. Witnesses said that most of the security forces carrying out arrests were wearing military clothing, but there were also men dressed in civilian clothes armed with rifles.

 "The forces would surround a building with a big number of cars, then go inside to arrest their targets," one witness told Human Rights Watch. "They also drove tanks through the streets to scare us by reminding us of the 1982 massacre." In February 1982, Syrian army commandos brutally crushed an anti-government rebellion in Hama, destroying entire neighborhoods and killing an estimated 10,000 people.

Another resident, who said he personally knew of at least 20 people who had been arrested, described what happened in his neighborhood, al-Mahatta, in the early hours of July 3:

When people heard the commotion [of security forces approaching], they ran outside and started chanting "Allah akbar," using megaphones to wake up everyone else. More and more people then came outside and started burning tires to block the roads. There was a small confrontation between those people and the security forces, who started shooting at the people. The people fought back by throwing stones.

Residents told Human Rights Watch that security forces opened fire in certain areas during the raids, killing at least 16 people and wounding dozens more. The National Organization for Human Rights, a Syrian human rights group, published a list of 22 killed.

On July 4, security forces shot `Amer Khalouf, 13, from Kazo village just west of Hama, while he stood in the street with other boys, said a local resident. Security forces also shot Naser al-Shami on al-Marabet Street while he stood with a group of young men who were watching their neighborhood, and residents took him to a local hospital, said a doctor and local activists interviewed by Human Rights Watch. They reported that al-Shami subsequently died from his injuries. A witness who was at the Hourani hospital at the end of the afternoon on July 4 reported that he saw nine wounded people who appeared to be in critical condition.

The arrest campaign and the shooting intensified on July 5, residents told Human Rights Watch. They provided Human Rights Watch with the names of 14 residents killed that day: Muhammad Bitar, Imad Khallouf, Ali al-Nahar, Hassan Sarakbi, Baha' Hablousi, Jamal Dalati, Khaled Dalati, Muhammad al-Qasem, `Imad Khalouf, Baha' Fayez al-Nahar, Ahmad Bitar, Fuad Mukhalalati, Abdel Salam Ibrahim al-`Ar`our, and Muhammad Sueid. All died from bullet wounds, based on the testimony and videos of their bodies posted on YouTube, though the exact circumstances of their deaths remain unclear.

A Hourani hospital official told Human Rights Watch that the hospital received the bodies of four people on July 5 and treated 60 people with gunshot wounds, 7 of whom remained in critical condition. The Syrian army surrounded the Hourani hospital on July 5 scaring many of those who had assembled around the hospital, but did not enter the facility or arrest any of the wounded there.

"Syria's security forces still believe they can shoot their own people into submission," Whitson said. "But their bloody tactics only serve to deepen the gap between citizens and the institutions that are supposed to protect them."

Among those arrested on July 3 were Mohammed Sayed al-Sayed, from al-Baath neighborhood; Amr al-Aqrah, from al-Sejouah; Nadim Hassan al-Qar'aour, from al-Sejouah; Hashim al-Aqrah; and Hossan Lebaniyah. A family member of Mohammed Sayed al-Sayed told Human Rights Watch that security forces arrested 35 young men in al-Hadr neighborhood at 5 a.m. on July 3, some from their homes and some from al-Manakh mosque, and arrested three women in al-Salumiyah neighborhood. Women were also assaulted and beaten in al-Arbayin neighborhood, this person said.

Those arrested on July 4 and 5 include Ashraf Daood, Hamzi Hawa, Hazem Ajneed, Tarek al-Judu`, Ezz al-Deen Malas, `Amer al-Shami, Hamdo al-Judu`, Faraj al-Judu`, Sam al-Achkar, Abdel Azeez Handawi, Muhammad Telkawi, Mu`ad Zaydan, Ziad Zaydan, Abdel Aziz Zaydan.