Fifteen students at a central China school have been diagnosed with hepatitis A, and investigators suspect water pollution is to blame, the local government said Monday.

The patients are all 12th graders at No. 4 High School of Qiyang County in Yongzhou City of Hunan Province, the county government said in a statement.

It said the first case was reported on Feb. 17 and the latest was diagnosed on Sunday. All patients are being treated at the People’s Hospital in Qiyang County.

A joint investigation has been launched by disease control and prevention authorities at county, city and provincial levels. Investigators found the students had drunk water from a well on campus, and suspected contaminated well water was to blame for their illness.

But the exact cause has yet to be confirmed, the county government said.

School authorities confirmed all 12th graders had resumed classes in mid-February, at least a week before the spring semester began, to cram for the college entrance exam scheduled for early June. As tap water supply was cut during the winter break, well water was temporarily used.

School authorities had organized health checks for every student and teacher who drank from the well, and vaccinated the other 12th graders against the virus.

The school has more than 4,000 students, ranging from 7th to 12th grade. About 1,200 are in 12th grade and all of them are boarders.

The county government is watching the situation closely as the hepatitis A virus can be latent for 15 to 45 days.

First Minister Carwyn Jones is launching the inaugural ‘Wales in London’ week in London this morning. He will make a keynote speech promoting Wales as a key investment location at the Royal Institution of Chartered Surveyors’ (RICS) headquarters in Parliament Square.

The First Minister will also host a St David’s Day reception at Lancaster House to engage with London-based foreign diplomats and businesses with an interest in Wales.

On Tuesday, the First Minister is travelling to Washington and New York to meet with companies looking to invest in Wales and will discuss trade and business links with political representatives.

While in New York, the First Minister will host a reception to mark the launch of a new £5 million international tourism campaign. The 2017 Year of Legends campaign will show Wales is a country rich in history, storytelling and creativity.

Meanwhile, Finance and Local Government Secretary Mark Drakeford will be celebrating St David’s day in Brussels, where he will be hosting the annual evening reception at the British Residence. 

Mark Drakeford will also hold a series of meetings with representatives from European Institutions and the UK’s Permanent Representative to the EU, Sir Tim Barrow, to discuss Wales’ priorities as Britain prepares to leave the EU.

Environment and Rural Affairs Secretary, Lesley Griffiths, is travelling to the United Arab Emirates this week to promote Wales’ thriving food and drink industry. During her trip, Lesley Griffiths will join twenty five Welsh food and drink producers at Gulfood, the world’s largest food trade event, and hear about plans for the next World Expo, taking place in Dubai 2020.

First Minister Carwyn Jones said:

“St David’s Day 2017 marks a step-change in our ambition to promote Wales to the world like never before.

“During these times of great change, there is a need for us to work even harder to raise Wales’ international profile and performance. In recent years we have seen record inward investment to Wales; record tourism figures – including an increase of 12% over the last twelve months alone – while our products are now exported across the globe. We are, therefore, well placed to take on the challenge.

“This week, my Cabinet and I will celebrate our national day by promoting Wales around the world and celebrating everything we have to offer. We will use every opportunity to showcase our unique culture, history and language – and demonstrate that Wales is a great place to visit and do business.”

The international crude oil price of Indian Basket as computed/published today by Petroleum Planning and Analysis Cell

China’s top environmental watchdog has criticized authorities of Shijiazhuang, capital city of Hebei Province, which neighbors Beijing, for worsening air quality and insufficient efforts in environmental protection.

The air quality in Shijiazhuang has worsened sharply since October 2016 and most pollution indicators deteriorated in January and February of this year, the Ministry of Environmental Protection (MEP) said Monday after a recent inspection team to the city led by Chen Jining, minister of environmental protection.

In January this year, PM2.5 density in Shijiazhuang surged 51.5 percent from a year earlier to 200 micrograms per cubic meter, the MEP said in a statement.

Chen attributed the situation largely to lax environmental efforts of local governments, especially those at the county and township levels, inefficient management, a cluster of highly polluting enterprises and poor implementation of response measures to tackle severe pollution.

Chen urged more efforts in locating the source of pollutants, reducing pollutant emission, strengthening supervision over key enterprises, pressing ahead with industrial upgrading and improving efficiency of environmental protection.

Chinese cities suffered from more days of air pollution in January, with Shijiazhuang being the worst polluted among the nation’s 74 major cities, the MEP said last week.

China is intensifying efforts to fight pollution and environmental degradation after decades of growth left the country saddled with problems such as smog and contaminated soil.