BEIJING—Chinese authorities appeared to tighten their grip over a restive portion of western China following a spate of ethnic Tibetans setting themselves on fire to protest heavy-handed Chinese rule.

The state-run Qinghai News Net reported Thursday that authorities in western Qinghai province's Huangnan prefecture were intensifying patrols by paramilitary security forces, stepping up check points to block outsiders from entering and cracking down on audio-visual equipment that helps Tibetans tune in to overseas news programs.

...