This photo provided by the Ibaa News Agency, the media arm of al-Qaida's branch in Syria, purports to show part of a Syrian warplane that was shot down by rebel fighters over Idlib province in Syria, Wednesday, Aug 14, 2019. The Britain-based Syrian Observatory for Human Rights, a war monitor, said the warplane was shot down on the southern edge of Idlib province, while activist Taher al-Omar who has close links with militants said it was a Russian-made SU-22. The caption in Arabic reads:

BEIRUT (AP) — Syrian forces gained more ground from insurgents in the country's northwest on Thursday, edging closer to a major rebel-held town a day after militants shot down a government warplane in the area.

The government offensive, which intensified last week, has displaced nearly 100,000 people over the past four days, according to the Syrian Response Coordination Group, a relief group active in northwestern Syria.

Syrian troops have been on the offensive in Idlib and its surroundings, the last major rebel stronghold in Syria, since April 30. The region is home to some 3 million people, many of them displaced in other battles around the war-torn country.

The fighting over the past days has been concentrated on two fronts as government forces march toward the town of Khan Sheikhoun from the east and west. The latest offensive also aims to besiege rebel-held towns and villages in northern parts of Hama province, according to opposition activists.

The town of Khan Sheikhoun is a stronghold of al-Qaida-linked Hayat Tahrir al-Sham, the most powerful group in the rebel-held areas. The town was the scene of a chemical attack on April 4, 2017 that killed 89 people.

At the time, the United States, Britain and France pointed a finger at the Syrian government, saying their experts had found that nerve agents were used in the attack. Days later, the U.S. fired 59 U.S. Tomahawk missiles at the Shayrat Air Base in central Syria, saying the attack on Khan Sheikhoun was launched from the base.

The Syrian government and its Russian allies denied there was a chemical attack.

The government-controlled Syrian Central Military Media said Thursday that pro-government fighters captured three small villages, just west of Khan Sheikhoun.

The Britain-based Syrian Observatory for Human Rights, a war monitoring group, said the villages fell in the morning hours and that the town of Khan Sheikhoun is being bombarded relentlessly.

Syrian state media confirmed insurgents had downed the government plane on Wednesday. An al-Qaida-linked group has released a video of the pilot in which the handcuffed man identified himself as a lieutenant colonel in the Syrian air force.

In the video, the pilot says his fighter jet was shot down when he was carrying out a mission near Khan Sheikhoun.

The U.N. said Thursday that a series of airstrikes in the Ma'arat Humeh area in southern Idlib led to the deaths of a paramedic, an ambulance driver and a rescue worker, adding to the more than 500 civilian fatalities documented in the country by the United Nations in the past 3 1/2 months.

Mark Cutts, the U.N. deputy regional humanitarian coordinator for the Syria crisis, said Wednesday's airstrikes, which destroyed an ambulance, highlight again "the horror" of what is happening in Idlib, where 3 million people remain trapped by fighting with nowhere to flee.

This photo provided by the Ibaa News Agency, the media arm of al-Qaida's branch in Syria, purports to show part of a Syrian warplane that was shot down by rebel fighters over Idlib province in Syria, Wednesday, Aug 14, 2019. The Britain-based Syrian Observatory for Human Rights, a war monitor, said the warplane was shot down on the southern edge of Idlib province, while activist Taher al-Omar who has close links with militants said it was a Russian-made SU-22. The caption in Arabic reads:
This photo provided by the Ibaa News Agency, the media arm of al-Qaida's branch in Syria, purports to show part of a Syrian warplane that was shot down by rebel fighters over Idlib province in Syria, Wednesday, Aug 14, 2019. The Britain-based Syrian Observatory for Human Rights, a war monitor, said the warplane was shot down on the southern edge of Idlib province, while activist Taher al-Omar who has close links with militants said it was a Russian-made SU-22. The caption in Arabic reads: