Triggered searches of delayed or extended VHE GRB emissions with HAWC

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory, installed at an altitude of 4100 m asl in the state of Puebla, Mexico, has recently completed its first year of full operations. Thanks to its instantaneous field of view of 2 sr and to its high duty cycle (≥ 95%), HAWC is an ideal instrument for detecting transients such as gamma ray bursts (GRBs) with emissions in the TeV regime, thus complementing the observations by satellites. In this work we focus on triggered offline searches for high energy emission from GRBs reported by the Fermi-LAT, and Swift instruments. We show our results on searches for delayed TeV emissions, as well as for emissions longer than T90 in the HAWC data from its first year of operations.