In some cities, including Bet Shemesh, the city administration has instructed the relevant departments to dismantle and remove bonfires that have been built around town, and that has already begun to happen. 

Additionally, the administration of the Firefighting Authorities, or whatever they call themselves, has just signed an order banning all bonfires around the country for Lag B'Omer due to potential danger, as extremely hot and dry weather is expected. Some locations have been explicitly excepted from the order, including Kever Rashbi in Meron, but in general, bonfires will not be allowed. (source: Ynet)

And, Rav Davidovitz, a rav in RBS and the rav in charge of the eruvs of Bet Shemesh, has explained another problem caused by the bonfires. Rav Davidovitz says, and shows, that many bonfires have been placed under or very near to eruv wires. The heat from the fire, if not the fire itself, will melt and destroy many of the wires. 

With Lag B'Omer being Thursday night this year, that will make it very difficult for his team of eruv maintenance people to fix the eruv before Shabbos. There just will not be enough time. Rav Davidovitz says they will do their best and repair whatever is necessary and hopefully will have everything ready in time, but parents should help out by having the children build their bonfires further away from the eruv wires.  

With the order being signed by the fire people to prohibit bonfires, Rav Davidovitz's issue might actually no longer be a problem...