Source: Volcano Discovery

Suwanose-jima (Ryukyu Islands): The activity of the volcano has become more intense during the past days. Several ash plumes were detected by Tokyo VAAC and blight glow is intermittently visible on the webcam.
Most likely, the volcano has started another phase of intense, intermittent strombolian explosions.

Semeru (East Java, Indonesia): Access to the mountain was closed after a 26 year-old Swiss climber has been missing for 10 days now since he climbed the volcano on 3 June.
The young man who climbed the volcano without a guide was reported missing by a travel companion who had been in a different location for a few days and could notice his absence only 3 days later. Despite intense efforts, local search-and-rescue teams have so far been unsuccessful to locate the young man. It can only be speculated about his fate, but chances of his survival seem dwindling.
 
The most likely causes for the accident are lost orientation on the mountain during ascent or descent, or perhaps falling into one of the difficult-to-access steep ravines draining on the volcano’s steep slopes.

Suretamatai (Banks Islands, Vanuatu): The alert level of the volcano (also known as Vanua Lava) was recently raised a notch from 0 to 1 (on a scale of 0-4). No details about volcanic unrest are available, but presumably, the Vanuatu Geohazards Observatory recorded elevated seismic activity from the volcano.
Residents and tourists are reminded to stay outside of areas near the crater and in particular avoid the Sulfur River (E flank) were there is a high risk of volcanic gas emissions.

Popocatépetl (Central Mexico): A moderately strong vulcanian explosion occurred yesterday morning at 11:17 local time, producing a mushroom-shaped ash plume that rose approx. 3 km above the summit and dispersed in westerly directions.
Today, the volcano has been mostly calm with only minor emissions mainly of steam and gas.
The activity of the volcano itself has been very stable over the past months and at overall low to medium levels only; while lava is slowly accumulating in the summit crater, this growth of the lava dome is occasionally interrupted by explosions such as this one.

Currently erupting:

Ambrym (Vanuatu): active lava lakes in several craters (updated 13 May 2016)
Bagana (Bougainville Island, Papua New Guinea): intermittent mild ash emissions (updated 23 May 2016)
Batu Tara (Sunda Islands, Indonesia): strombolian explosions, ash plumes up to 500 m, extrusion of a small lava dome with rockfalls (updated 28 Nov 2015)
Bristol Island (United Kingdom, South Sandwich Is): new eruption since late April 2016 (updated 6 Jun 2016)
Colima (Western Mexico): intermittent mild to moderate explosions (updated 1 Jun 2016)
Copahue (Chile/Argentina): seismic unrest, occasional ash venting (updated 22 Mar 2016)
Dukono (Halmahera): mild strombolian activity, continuous intense ash emissions (updated 1 Jun 2016)
Erebus (Antarctica): active lava lake in summit crater (updated 8 Dec 2014)
Erta Ale (Danakil depression, Ethiopia): overflowing lava lake (updated 2 Mar 2016)
Fuego (Guatemala): lava flows on S and W flanks, lava fountaining from summit vent (updated 23 May 2016)
Ibu (Halmahera, Indonesia): stromolian and phreatomagmatic explosions (updated 29 Oct 2015)
Karymsky (Kamchatka): occasional small explosions, thermal anomaly (updated 5 May 2016)
Kerinci (Sumatra): intermittent ash explosions (updated 5 Jun 2016)
Kilauea (Hawai’i): new surface lava flows from breakouts N and NE of Puu Oo since 24 May 2016 (updated 28 Apr 2015)
Kliuchevskoi (Kamchatka): mild strombolian activity in summit crater (updated 4 Jun 2016)
Langila (New Britain, Papua New Guinea): ash emissions (updated 13 May 2016)
Masaya (Nicaragua): active lava lake ini summit crater (updated 6 Jun 2016)
Nyiragongo (DRCongo): new vent on crater floor (updated 1 Jun 2016)
Ol Doinyo Lengai (Tanzania): effusion of natrocarbonatite lava inside the crater (updated 8 Jul 2013)
Pacaya (Guatemala): intense spattering from intra-crater cone (updated 29 Mar 2016)
Popocatépetl (Central Mexico): degassing, sporadic explosions, slowly growing lava dome (updated 13 Jun 2016)
Reventador (Ecuador): lava flow on SW flank (updated 24 Feb 2016)
Sakurajima (Kyushu, Japan): sporadic vulcanian explosions from Minamidake and Showa crater (updated 3 Jun 2016)
Sangay (Ecuador): mild strombolian activity in summit crater (updated 20 May 2016)
Santiaguito (Guatemala): intermittent strong explosions from growing Caliente dome (updated 26 May 2016)
Semeru (East Java, Indonesia): lava flow, small strombolian explosions (updated 13 Jun 2016)
Shiveluch (Kamchatka): growing lava dome (updated 9 May 2016)
Sinabung (Sumatra, Indonesia): continuing pyroclastic flows (updated 10 Jun 2016)
Stromboli (Eolian Islands, Italy): weak, intermittent strombolian explosions (updated 23 May 2016)
Suwanose-jima (Ryukyu Islands): strombolian explosions (updated 13 Jun 2016)
Turrialba (Costa Rica): intermittent mild to moderate ash emissions (updated 3 Jun 2016)
Villarrica (Central Chile): lava lake in summit crater, spattering, strombolian explosions (updated 4 Apr 2016)
Yasur (Tanna Island, Vanuatu): ash emissions, weak strombolian explosions (updated 13 Nov 2015)

More continued coverage and updates at Volcano Discovery: Volcanic Activity Worldwide