BEIRUT - Residents of the besieged city of Fallujah are starving. Iraqi government forces should urgently allow aid to enter the city, and the extremist group Islamic State, also known as ISIS, which captured the city in early 2014, should allow civilians to leave.

“The people of Fallujah are besieged by the government, trapped by ISIS, and are starving,” said Joe Stork, deputy Middle East director. “The warring parties should make sure that aid reaches the civilian population.”

Since government forces recaptured nearby Ramadi, the capital of Anbar governorate, in late December 2015, and the al-Jazira desert area north of Fallujah in March 2016, they have cut off supply routes into the city, three Iraqi officials said. Tens of thousands of civilians from an original population of more than 300,000 remain inside the city.

Human Rights Watch has not had access to Fallujah, and it is very difficult to get information from the remaining residents because ISIS prohibits the use of mobile phones and the Internet. Residents sometimes manage to catch a cell tower signal at night and are able to respond to some messages, including several that Human Rights Watch relayed via rights activists in Baghdad. Human Rights Watch was recently able to speak with one person in Fallujah and to seven others from the area who are in contact with people there.

Iraqi activists who are in touch with Fallujah families said that people were reduced to eating flat bread made with flour from ground date seeds and soups made from grass. What little food remains is being sold at exorbitant prices. A 50-kilogram sack of flour goes for US$750, and a bag of sugar for $500, whereas in Baghdad, 70 kilometers to the east, the same amount of flour costs $15 and of sugar $40, one Fallujah resident said. In late March 2016, a Fallujah medical source told Human Rights Watch that each day starving children arrive at the local hospital and that most foodstuffs are no longer available at any price.

An Iraqi official in touch with some Fallujah families provided Human Rights Watch with a list of 140 people, many elderly and young children, whom the official said had died over the past few months from lack of food and medicine. The official did not want the names of the dead published for fear that ISIS, which prohibits contacting people outside the city, would punish relatives of the dead.

A new campaign, “Fallujah Is Being Killed by Starvation,” has sought to draw attention to the impact of the siege. In one recent video that Baghdad-based activists provided to Human Rights Watch, an unidentifiable woman says she is from Fallujah and that her children are dying because there is no rice, no flour – not even local dates – and the hospital has run out of baby food.

The Facebook account “Fallujah is my city” (“فلوجة مدينتي”) posted a video on March 23, 2016, showing several lifeless bodies in a body of water. Baghdad-based activists said that it shows a mother who drowned herself and her two children because she could not find food. Another activist from Fallujah, now based in Iraqi Kurdistan, corroborated this account based on information from relatives still in Fallujah.

On March 24, the World Food Programme said that it remained “concerned about the food security situation in besieged Fallujah, [where] many food items were unavailable in markets.”

Iraqi government troops and the Popular Mobilization Forces, an auxiliary paramilitary force, are keeping shipments of food and other goods from reaching the city, two Iraqi officials and other sources said. The Defense Ministry, Baghdad Joint Operations Command, and Popular Mobilization Commission did not respond to Human Rights Watch requests for comment.

Civilians inside Fallujah have been unable to leave, Human Rights Watch said. An Iraqi lawyer who has maintained phone contacts with people in the city told Human Rights Watch that on March 22, ISIS executed a man for trying to leave the day before. “He walked straight up to the ISIS checkpoint and told them he wanted to leave because he couldn’t take the situation any longer,” the lawyer said. “ISIS brought him into town and executed him.”

Three people with connections in Fallujah informed Human Rights Watch in late February that ISIS had executed a family trying to leave. Their extended family revolted against ISIS, and ISIS then jailed more than 100 men taking part. A journalist with sources inside Fallujah confirmed that ISIS was preventing people from leaving and punishing those trying to do so. On March 30, the Popular Mobilization Forces said that ISIS had executed 35 civilians in Fallujah for trying to escape.

“Islamic State has shown utter disregard for protecting civilians in conflict,” Stork said. “It should not add mass starvation to its miserable record and should immediately allow civilians to leave Fallujah.”

Lise Grande, the United Nations deputy special representative in Iraq, said on February 20 that, “people are trying to leave the city but are prevented from doing so.” A local official told Human Rights Watch on March 25 that the government had opened three exit routes for civilians in Fallujah to flee the city, which Anbar governor Suhaib al-Rawi repeated in a March 29 report in Al-Sabah newspaper. However, Baghdad-based activists said that ISIS was still blocking civilians from leaving.

The laws of war do not prohibit sieges of a belligerent’s military forces. However, they do prohibit starvation of the civilian population as a method of warfare, which is a war crime. Both sides also need to take all feasible steps to evacuate the civilian population from the vicinity of military objectives.

Parties to a conflict are prohibited from attacking objects indispensable to the survival of the civilian population, such as food and medical supplies, agricultural areas, and drinking water installations. They are obligated to facilitate rapid and unimpeded humanitarian assistance to all civilians in need, and may not deliberately block humanitarian aid or restrict the freedom of movement of humanitarian relief personnel.

In 1998, Iraq reported to the International Committee of the Red Cross on its application of the laws of war that, “refraining from the use of embargoes on food and medicine as a weapon by one of the conflicting parties is a fixed and established principle which has been applied by the Iraqi armed forces in armed conflicts.”

Civilians in Fallujah have also suffered considerable harm from the fighting, Human Rights Watch said. Government aircraft and artillery have carried out numerous attacks, which Fallujah residents say have killed many civilians. Neighbors reported to one former resident that on November 27, 2015, bombings killed 12 people in his neighborhood, including nine children. On August 13, aerial bombs struck Fallujah’s children’s hospital, killing several people, a relative of a staff member of the hospital told Human Rights Watch. A medical source in the city, whose information Human Rights Watch could not confirm, said that since January 2014, 5,769 combatants and civilians have been injured and 3,455 killed, roughly one-fourth of them women and children.

“The humanitarian picture in Fallujah is bleak and getting bleaker,” Stork said. “Greater international attention to the besieged towns and cities of the region is needed or the results for civilians could be calamitous.”