MENEMENG, Indonesia - An environmental activist and his family survived an attack on their lives early Sunday morning after assailants barricaded them inside their home and set it on fire. Murdani heads a chapter of Indonesia's largest environmental NGO, the Indonesian Forum for the Environment (Walhi). At around 3 a.m., he and his wife woke to the smell of burning on the second floor of their home in Menemeng village on Lombok, an island next to Bali. Over the past few months, Murdani had noticed people watching his house. He had recently taken to sleeping on the front porch in order to keep guard, though on this night he slept upstairs. Upon waking, Murdani and his wife immediately woke their two children. Murdani grabbed the younger one and rushed downstairs to find the front door on fire. The fire had surrounded part of the house and was spreading inside. His wife brought the older child down by way of the roof of a kiosk next door. Seeing her shouting, the neighbors rushed over to help. It took them 45 minutes to douse the flames. After dawn broke and the police arrived, they found a pillow under the front wheel of Murdani's car, apparently used to set it alight. They also found a plastic bag that smelled of gasoline by the house. Whoever started the fire had covered the security camera above the front door with a hat. They used a wooden chair to jam the door shut and a bamboo table to block another door. "The goal was to trap us inside," Murdani told Mongabay two days after the attack. Precisely why Murdani was targeted is not yet clear. The list of contentious development projects he has spoken out against in West Nusa Tenggara province, where he heads Walhi's operations, is long - from the reclamation of Bima Bay on the neighboring island of Sumbawa to gold mining on Lombok. However, Murdani suspects it was his work on sand mining that prompted the attack. Sand mines abound in the part of Lombok where Murdani lives. Under his leadership, Walhi's chapter in the province has fought illegal sand mines and urged the government not to issue permits for new sand mines. A year ago, residents asked Murdani to help advocate for the rejection of a proposed sand mine on the border of Menemeng and Bilebante, a village known as an ecotourism destination. Residents have complained the sand mining has resulted in damaged roads, landslides and cloudy water. At one point the developers behind a controversial plan to reclaim Bali's Benoa Bay floated plans to dredge sand from Lombok to be used as infill for the massive tourism project, although the provincial government rejected the proposal. "We've received a lot of threats by text message," Murdani said. There are many players in the local sand mining industry. Murdani doesn't want to speculate as to the culprit. He wants the police to handle it, although Walhi has formed its own team to investigate the attack. Murdani's case is not an outlier, said Puri Kencana Putri, campaign manager with Amnesty International. She pointed to the 2015 murder of Salim Kancil, a farmer who organized protests against a sand mine in Lumajang, East Java; and an attack last November on the office of the Mining Advocacy Network, or Jatam, in East Kalimantan province. "In Murdani's case, we know he advocates for and defends people's rights in the natural resource and extractive sectors, including mining," Puri said. "There are groups who don't like what he does." She called on the government to ensure protection for Murdani and his family. From 2010 to 2018, there were 171 recorded cases of violence against activists in Indonesia, according to Ainul Yaqin from the Indonesian Human Protection Foundation (YPII). Most of the victims were environmental activists. Muhammad Isnur of the Indonesian Legal Aid Foundation called on the police to focus on catching not just the people who attacked Murdani's house, but whoever put them up to it. "They've got to go after the mastermind," he said. However, he was pessimistic about the police getting to the bottom of the case, citing the lack of progress in the Jatam investigation.