Some 900 villagers in Kenya are surrounded by armed militiamen amid a territorial dispute between local communities, officials say.
Gunmen from the Pokot community are reported to have cut off the Turkana village of Lorogon for the last four days.
They attacked three nearby police camps on Saturday.
Kenyan TV reported that mediation talks between the Pokot and the Turkana are due to be held on Sunday.
The regional governor told Kenyan media that the village was facing a humanitarian crisis after being cut off for four days.
"More than 900 people, mostly women and children, cannot go out to look for water and food because they are surrounded by gunmen," Josphat Nanok was quoted by the Kenyan Press Agency as saying.
The National Disasters Operations Centre said the siege "follows a border dispute" between the two sides.
"Police officers and reservists [are] combating the bandits in Turkana, but there is heavy resistance," it said in a tweet.
Clashes between the Turkana and Pokot tribes tend to be over allegations of cattle rustling.