MANILA, Philippines — Signal No. 1 has been raised in Cagayan, Isabela and Catanduanes as Tropical Storm Leon maintained its strength while decelerating over the Philippine Sea, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said Monday.

Under the storm signal were the eastern portion of mainland Cagayan (Santa Ana, Lal-Lo, Gattaran, Baggao, Santa Teresita, Gonzaga and Peñablanca), the eastern portion of Isabela (Maconacon, Divilacan, Ilagan City, San Pablo, Cabagan, Tumauini, Palanan, San Mariano and Dinapigue), and the northeastern portion of Catanduanes (Pandan, Bagamanoc, Panganiban and Viga).